Police Maj-General Piya Uthayo said the extent of crowd-control operations would depend on the protesters and their activities at Samsen train station, adding that it looked like the rally organisers were prepared to continue protesting for a long time.
The ISA currently covers |three Bangkok districts where Government House and Parliament are located. The enforcement expires this month.
As for maintaining peace and order, police and rally organisers have reached a two-point agreement:
The protesters will remain within the rally site, which has been marked from the Sethsiri-Kamphaeng Phet intersection in front of the Chuchan shop to the train station.
The protesters will be allowed to set up camp in the area and can use loudspeakers from 6pm to midnight.
Police have also reminded protesters that their rally site is located in an area that can be attacked by a third party, explaining that assailants can throw objects at them from the overhead expressway. The organisers have also been warned to control the crowds and ensure the train traffic is not blocked.
Apart from the anti-amnesty protesters, some 600 farmers have also been camping out near the train station, and anti-riot forces are worried about possible brawls between the two groups.
Meanwhile, National Police chief General Adul Saengsingkaew has instructed his subordinates to ensure strict enforcement of the law, comply with crowd-control procedures and keep their actions transparent.
When he was updating Prime Minister Yingluck Shinawatra about the situation, the police chief said, the PM ordered that the authorities adhere to the rule of law when dealing with protesters.
He said the police expected as many as 20,000 to 30,000 people to join the protest, adding that the anti-amnesty rally and the rubber farmers protesting in Prachuap Khiri Khan might be linked.
Some 40 companies of riot forces have been mobilised to ensure peace in the area.
Early yesterday, a number of Democrat MPs were seen supervising the setting up of the rally site.
Though roads near the site remained open, traffic was being redirected in some areas to facilitate flow.
Separately in Trang, more than 50 police officers were deployed to safeguard the provincial hall as a precautionary measure. Some 2,000 protesters are expected to show up in the area to voice opposition to the amnesty bill.