Key figures of the Wadah group have denied any involvement in last week's multiple attacks in seven provinces, saying they have been made a scapegoat for what happened.
It is the first time the Wadah group, an influential group of Muslim politicians in the deep South, has spoken about the matter. The group has often been fingered as the primary suspects allegedly involved in several violent incidents in the far South, including the car bombing at the Central Festival Samui mall in Surat Thani on April 10 of last year, and the latest bombing and arson attacks in Prachuap Khiri Khan and six southern provinces.
Authorities said evidence suggested the devices used in the bomb and arson attacks in the seven provinces were similar to those assembled in the deep South for previous attacks.
Police investigators on Monday cited an expanded investigation indicating that the plot was engineered by "a prominent political figure" in the restive region.
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Earlier, the Wadah group was accused of being behind an audio clip "distorting" the content of the draft charter and disseminated in the far South before the Aug 7 referendum. The group denied the allegation while saying it did not support the draft charter.
National police chief Chakthip Chaijinda previously said it was likely last week's attacks were politically motivated, particularly after the referendum results.
Following the referendum, the three southernmost provinces had double the national rate of spoiled ballots.
While invalid ballots nationwide were 936,209, or 3.15%, the percentage was 7.4% in Pattani, 6.54% in Yala and 7.1% in Narathiwat.
Former Pheu Thai MP for Yala Wan Muhamad Nor Matha, leader of the Wadah group, told the Bangkok Post that there was no way the attacks could be linked to the outcome of the referendum.
"The referendum is over now. Whether one likes it or not, there is nothing one can do about it. As politicians, all we can do is to wait for election day," he said.
"Police must investigate the case carefully and provide solid evidence proving who was involved in the attacks before jumping to conclusions."
"Jumping to conclusions will not only ruin the case, but also ruin the reputation [of the police]."
"I don't want to comment on whether the Wadah group has been made a scapegoat. In reality, we have nothing to do with this," he said, adding that the Wadah group has denounced such acts of violence.
"We are politicians in the parliamentary system. The thought of harming innocent people and destroying their property has never crossed our minds."
"We decline to be involved in this kind of battle, but we will fight only in the political arena," Mr Wan Nor said, adding the attacks occurred in the upper South, which is unfamiliar territory for the Wadah group.
He noted that violence had been rampant in the deep South before and after the Aug 7 referendum, and last week's attacks in the seven provinces are unlikely to be linked with the referendum.
"Police must find the real culprits and it's wrong to prosecute any scapegoats," Mr Wan Nor said.
Najmuddin Umar, another Wadah key figure and a former Matubhum Party MP for Narathiwat, told the Bangkok Post he had no information about last week's attacks.
He added it came as no surprise that authorities linked the attacks to political figures in the three southernmost provinces because they had done this before.
Mr Najmuddin cited the Samui bombing last year.
"It is normal for the intelligence units to try to find a way out. But they have still been unable to give an answer to the public."
"The Wadah group has been accused of being involved in numerous violent incidents for decades. I am used to it. We have cooperated with authorities all along, and we do not blame them if they do not understand the situation in the local area."
"There is no need for me to explain to anyone because I have no information to give. This is similar to what happened in Samui last year. Police targeted me, but eventually there was nothing."
He said the Wadah group engages in politics openly, and there is no need for the group to go underground.
Mr Najmudding was once accused of being a member of the Bersatu separatist group and faced charges, including treason. However, the Criminal Court acquitted him of the charges on Dec 15, 2005.
Areepen Uttarasin, a former Matubhum MP for Narathiwat, told the Bangkok Post that he believed the attacks in the seven provinces were not linked to insurgents in the deep South, and that they had nothing to do with any political groups upset with the referendum's outcome.
The insurgents in the three southernmost provinces of Yala, Pattani and Narathiwat are unfamiliar with the six provinces in the upper South and Prachuap Khiri Khan so it is difficult for them to perpetrate violence outside the far South, he said.
"It is irrational to link the referendum to the attacks. Defeat in the referendum is not a matter of life or death."
Meanwhile, military sources did not rule out the possibility that the Barisan Revolusi Nasional was behind the attacks.
"They are aware of Thai key events like the referendum and the Queen's birthday. They sent messages that they didn't want the new charter until the 'Siamese' parliament -- whether elected or military -- addressed their Melayu Muslim identity as a group or state in the highest law," said intelligence sources in the South.