Two police complaints have been filed against student protest leaders -- which include an accusation of lese majeste -- after the weekend protest at Sanam Luang, according to the assistant commissioner of the national police force.
Pol Lt Gen Piya Utayo said the complaints against the protest leaders were filed with Chana Songkhram police station.
One complaint accused the protest leaders of lese majeste as defined by Section 112 of the Criminal Code, while the other is centred around the installation of a pro-democracy plaque at Sanam Luang, or Royal Ground, and the symbolic renaming of it as Sanam Ratsadon, or People's Ground.
Tul Sittisomwong, the leader of the so-called "multi-coloured shirts movement" who filed the lese majeste complaint, said the protest leaders had once again crossed the line.
"I don't mind if they talked about politics, the prime minister or the constitution because they have the right to do so, but not about the monarchy," he said.
Pol Lt Gen Piya said the police will take the strongest legal actions possible against the protesters and their backers for undermining the monarchy.
He added that several protesters have already been charged on both counts.
According to the police, around 10 protesters will be charged with violating the Public Assembly Act, as well as several sections of the Criminal Code, while up to four protest leaders will be charged with lese majeste.
Deputy police spokesman, Pol Col Kissana Phathanacharoen, said investigators are considering revoking the bail of some of the protest leaders, as they violated their bail conditions by attending the rally.
The Bangkok Metropolitan Administration (BMA) and the Fine Arts Department also filed complaints against the rally leaders at Chana Songkhram police station for breaking into Thammasat University grounds and Sanam Luang.
Deputy spokesman of the Metropolitan Police Bureau, Chiraphat Bhumichitr, said the BMA wanted the police to take action against the protesters for destroying barriers and fences at the university and damaging the concrete surfaces around Sanam Luang.
"The protesters damaged BMA properties and violated the Act on the Maintenance of the Cleanliness and Orderliness of the Country," said Pol Maj Gen Chiraphat.
Representing the Fine Arts Department, director of the Office of Archaeology Sathaporn Thiangtham accused the protesters of violating the Ancient Monuments, Antiques, Objects of Art and National Museums Act, as Sanam Luang is a historical site protected by law.
The plaque was confiscated and sent to forensic investigators.
Meanwhile, one of the protest leaders, Parit "Penguin" Chiwarak downplayed the removal of the plaque, saying the movement will simply recast and distribute similar plaques to be planted at public places across the city.
He also urged the public to take time off work to participate in the rally scheduled for Oct 14 as a sign of defiance against the government.
The protesters also announced a plan to hold another rally on Thursday at the parliament building.
While the student movement has garnered the support of many who are dissatisfied with the political situation, it also faced criticism.
Ex-president of the Federation of the Thai Capital Market Organizations, Worawan Tharabhumi, wrote on Facebook that she expected to hear what these protesters thought about challenges such as technology disruption and its effect on their future careers.
"I expected to see the students talk about threats they were facing, only to find that their real intention was to undermine the monarchy," she wrote.
"Installing the plaque and disrespecting the monarchy will not improve people's well-being or reduce equality in the society," he said, calling it "counterproductive".
She said the student protesters might push those who are frustrated with the government to take sides with the prime minister because they cannot tolerate people abusing the monarchy.
