Two weeks after 38 people were killed in a fire at the Mae Surin camp in Mae Hong Son province, the circumstances that led to the fatal blaze remain unclear.
SUSPICIOUS SMOKE: The police officer in charge of the initial investigation said he was puzzled by the black smoke created by the blaze. House fires usually produce white smoke, he said.
In the aftermath of the tragedy, which has been described as the worst to hit a border refugee camp in more than 25 years, the military has maintained a tight lid on the scene.
As well as the fatalities, more than 2,300 Karen and Karenni refugees were left homeless, 100 people were injured and 400 dwellings were destroyed.
While there has yet to be an official declaration of the cause of the fire, media reports have pointed to three possible explanations: a cooking accident, a forest fire and arson.
Spectrum visited the camp last week to get eyewitness accounts of what happened both before and after the fire.
GROWING CONTROVERSY
According to more than 20 refugees, including camp authorities and members of the local firefighting team, the blaze had nothing to do with cooking or a natural disaster. The eyewitnesses did, however, tell Spectrum that shortly before the fire broke out they had seen several aircraft flying over the camp.
CRITICAL CONDITION: Visitors stand beside the hospital bed of 14-year-old Cha Nay Choo in Chiang Mai. The teenager suffered horrendous burns while trying to rescue a fellow resident of the refugee camp.
Shally Than, the camp's chairwoman, also said there was no evidence of a forest fire that day and suggested that the blaze occurred too early for it to have been caused by people cooking.
''The fire started about 3pm, but people here don't usually start cooking dinner until 4 or 5pm,'' she said.
Also, the mother of the family that lived in the house in which the fire started told the local fact-finding team looking into the incident that she wasn't at home at the time, Shally Than said.
Sai Htun, who heads the fact-finding team, confirmed that the woman was away from home when the blaze started.
Several neighbours said the woman and her husband were away from the property at the time of the blaze, though they had left their child at home sleeping. The youngster was later rescued by a neighbour.
Neighbour and firefighter Kler Yeh Htoo said he believed the blaze started in the bedroom, not the kitchen, as he had seen smoke coming from the roof of his neighbour's house before he saw any flames.
''It was a sort of vapour at first, before becoming a fire,'' he said.
Several other eyewitnesses claim to have seen three white planes in the skies above the camp shortly before the fire erupted.
A 14-year-old boy said he spotted the aircraft while he was searching for vegetables on the hillside. He said one of the planes was flying lower than the other two.
'' They weren't helicopters, but small white planes,'' he said.
''The first one seemed to release something, like a white powder or smoke, while the other two were just flying around nearby. After a while, the first plane disappeared from sight and the other two followed it.''
The boy said that shortly after the planes flew away, he saw plumes of smoke billowing from the camp.
Supporting the idea that something was dropped on to the camp from the air, several witnesses said they saw small crystals falling on to the roofs of their homes. Some described the particles as looking like salt, while others said they resembled fertiliser.
A number of people who helped tackle the blaze said it seemed to intensify when they threw water on to it. They said they were also perplexed at how several houses escaped unscathed while neighbouring properties were razed to the ground.
Local firefighters described the fire as ''unlike any they had seen before'', adding that it spread rapidly in different directions.
Though the firefighters were equipped with little more than buckets of sand and water, residents said they had in the past successfully tackled two fires at the camp.
''When fires broke out before, we were able to douse them with the help of four or five people per house,'' Mr Kler Yeh Htoo said.
RESTRICTED ACCESS
Since March 24, two days after the blaze began, Thai border security forces have imposed strict restrictions on access to the camp. They have blocked visitors from distributing aid and allowed entry only to vehicles attached to authorised groups, such as the army and police, the eyewitnesses said.
FATAL TRAGEDY: An elderly woman refugee laden with belongings stands beside a row of victims of the deadly blaze. The fire, which broke out on March 22, claimed the lives of 38 refugees.
People attempting to deliver aid to the camp were told by soldiers to leave it at a collection office in Mae Hong Son's Khun Yuam district. They were informed that the supplies would be distributed later by officials.
Local authorities said that due to the high volume of official traffic in the area and damage to the main access road, the camp is now off-limits to all outsiders.
Spectrum reporters en route to the camp in a van were told by a military commander at a checkpoint in Ban Mae Sapin to turn back. He advised the team to return to Khun Yuam and seek official permission to enter the camp from the local district office.
''I am not authorised to let you through, so please go back and ask for permission to enter,'' the officer said.
After returning to Khun Yuam, officials at the district office told the Spectrum team to leave the supplies intended for the refugee camp with them.
A woman at reception said she too was unauthorised to grant them permission to enter the camp, repeating the claims of heavy official traffic and a damaged road.
After efforts to secure access through official channels failed, the Spectrum team finally managed to enter the camp by joining an aid convoy organised by Thai TV Channel 3.
Once inside it became immediately clear that despite the earlier claims by the military and local officials, there were not ''lots of official vehicles'' in the camp nor was the main access road badly damaged.
PROBE, RECONSTRUCTION UNDERWAY
According to Sally Thompson, director of the humanitarian agency The Border Consortium (TBC), the tragedy at the Mae Surin refugee camp is the worst she's ever witnessed.
PICKING UP THE PIECES: The redevelopment of the ravaged camp is expected to cost 13 million baht.
Since 1984, when the agency began providing supplies and aid to camps on the Thai-Myanmar border, there have been several major incidents.
''We have had natural disasters. We have had floods and fires. We have had cross-border attacks and mortar shelling of the camps. But never before has there been such a heavy loss of life,'' Ms Thompson said.
Despite the agency's near 30-year involvement with the camps it will not take part in any of the investigations into the fatal blaze at Mae Surin.
That will be the job of the Thai officials, Ms Thompson said.
Police have now begun an investigation and the area of the camp where the fire started is encircled with yellow tape and signs reading ''DO NOT ENTER''.
Several refugees told Spectrum they had been questioned by police, but none was told when the results of the probe would be released.
Running alongside the investigation is a clean-up process. Residents said there are three bulldozers on the site every day, clearing away debris and readying the land for redevelopment.
''Some of the reconstruction work should start next week,'' Ms Thompson said, adding that the TBC will be responsible for providing the necessary supplies for the work.
The rebuilding of the camp is likely to cost 13 million baht, she said.
LIFE GOES ON: After a harrowing experience, camp residents are keen to get their lives back on track.
Pol Col Nitinart Wittayawuthikul, the head of Khun Yuam district police, said that although he is no longer part of the investigation team, he is concerned that the clearance work at the site might result in the loss of key evidence.
The senior officer was transferred from Khun Yuam to Mae Hong Son after he refused to say the cause of the fire was ''accidental''.
After talking to more than 20 refugees, Pol Col Nitinart said he was certain the fire had not been caused by a cooking accident. He also said there was no evidence of the camp being engulfed by a forest fire.
What his team, which was one of the first to arrive at the camp after the blaze, did find were several clues to suggest the fire might have been started intentionally.
During an initial investigation, Pol Col Nitinart said he was told by more than 10 Karen refugees that they had seen burning objects falling from an aircraft flying over the camp a few minutes before the blaze erupted.
He also said that the way in which the fire spread was unusual.
''It began in a house in Zone 1 of the camp and then spread to Zone 4, rather than Zone 2,'' he said.
Something else that made the police officer suspicious was the colour of the smoke created by the fire.
''The smoke was dark, like when you burn chemicals or rubber tyres,'' he said.
''Smoke from house fires, because they're made from natural materials such as bamboo and leaves, is usually white.''
He suggested that liquid phosphorus might have been used to spark the fire.
An unnamed source from a police forensics team had earlier said that traces of phosphorus had been found in the area close to where the blaze is believed to have started.
The motive, if the fire was deliberate, could have been the high cost of maintaining the camp, Pol Col Nitinart said.
''Some people have told me to shut my mouth,'' he said.
''But I can't. Those refugees have spilt blood and lost lives. So I have to tell the truth.''
COUNTING THE COST
Of the more than 100 people injured in the Mae Surin camp blaze, the condition of 14-year-old Cha Nay Choo is the most critical.
Lying in a bed at Suan Dok Hospital, the boy is unable to speak and can communicate only by shaking or nodding his head. The fire left him with burns to 50% of his body and in his eyes the pain is clearly visible. Cha Nay Choo was injured trying to rescue a fellow resident from the blaze.
Because the boy's family lack the necessary documents they were not allowed to travel with him to the hospital. As a result he is being cared for by the International Rescue Committee (IRC), which provides the nutritional supplements he needs to remain in a stable condition.
Despite the best efforts of the IRC, Garrett Kostin, who runs the Best Friends Library in Chiang Mai, believes Cha Nay Choo needs better medical care, and has set up a fund to pay for it.
To give the boy the best treatment possible will cost about 6,300 baht a day, Mr Kostin said.
''Unless other organisations and individuals get involved, Cha Nay Choo will receive only very basic care,'' he said.
SCORCHED EARTH: Rescue workers survey the scene of devastation in the aftermath of the blaze. An official investigation is now under way to discover what caused the fire.
LOOKING FOR ANSWERS: Several residents of the camp said that shortly before the fire started they saw small crystals, resembling salt or fertiliser, falling from the sky on to the roofs of their homes.
A FINAL FAREWELL: Family and friends pay their respects to loved ones lost to the blaze, which a humanitarian group described as the worst its ever seen.
FIGHTING A LOSING BATTLE: Firefighters had only buckets of sand and water to tackle the raging inferno.