
Pol Lt Gen Worapong Chiewpreecha outlined the antiriot guidelines to be used to control the red shirts following a meeting with PM's Office Minister Sathit Wongnongtaey.
Authorities have estimated that some 20,000 to 30,000 people will show up in Sanam Luang before they march on to the seat of government.
"Police are ready to ensure peace during the demonstration and have drawn up contingency plans to deal with any eventuality, though the red shirts say they will be peaceful," Worapong said.
He reminded the red shirts that any attempts to stage a raid or destroy government property would not be tolerated.
Some 3,000 police officers have been mobilised to keep an eye on the rally and a similar number of soldiers will be on standby to provide reinforcements if necessary, he said, adding that police intelligence reports say the rally might last three days.
Security started getting beefed up since 6pm Monday so officials are ensured access to the government compound today. Although business inside Government House is expected to continue as usual, officials have been told not to drive to work. If they must drive, then their vehicles need to be parked at the nearby Royal Turf Club, also known as the Nang Loeng racetrack.
Under the antiriot guidelines, police have been instructed to avoid initiating violence and will only be equipped with shields and batons. If a clash erupts, officers have been told to only use their shields to control the violence. Crowd dispersal measures such as tear gas will only be used as the last resort.