Police have warned protest groups not to cause disturbances during the Asia-Pacific Economic Cooperation (Apec) summit later this week and stay at a designated protest site.

Police said some groups have asked the Bangkok Metropolitan Administration (BMA) for permission to hold gatherings at the Lan Khon Muang square near City Hall from today until Friday.

Bangkok governor Chadchart Sittipunt on Monday said he was concerned about the planned demonstrations during the summit.

The BMA will make the Lan Khon Muang square available for any political gatherings during the summit, Mr Chadchart said. He said the Ratsadon, Tha Lu Fa and Phai Daodin protest groups have sought permission to hold demonstrations until Friday, adding they have been asked to limit their activities to the designated site.

A security source said the group calling itself "Citizens Stop Apec 2022" will hold a gathering at Asok intersection tomorrow and walk to the Queen Sirikit Convention Center, the summit venue, to hand letters to Apec leaders.

The group on Tuesday handed letters to the Canadian, Australian, French, New Zealand, and US embassies to relay their messages to Apec leaders attending the summit in Bangkok. In the letter, the group accuses the government of human rights violations and demanded Prime Minister Prayut Chan-o-cha resign.

Road closures started from today to Saturday on Ratchadaphisek Road between the Asok Montri and Rama IV-Klong Toey intersections and on Duangphitak Road.

Workers delivering goods and mail to people in those areas can seek permission from police officers at  checkpoints to gain access to the roads.

Shuttle buses will also be available for people living and working in and around the area.

The navy has also been assigned to ensure security for Apec leaders and delegates staying at hotels along the Chao Phraya River, he said.