"I have proposed them before and I am going to do so again," the assistant Army chief said.

He would not reveal details of the measures pending discussions with officials.

"If they don't listen, I will just have to let the community know," Saprang warned.

The monitoring measures were like an inoculation, he said. They would be effective in preventing not just terror attacks and sabotage but also crimes.

On Saturday night, a small bomb exploded in a phone booth at the mouth of Soi Rajvithi 24. The explosion slightly injured a 22-year-old man.

Police were declining to narrow the scope of the investigation into who was responsible.

Metropolitan Police chief Lt General Adisorn Nonsee said at this point there was no clear evidence to link the explosion to people in uniform or any political groups.

"Please give police officers working on the case some time," he said.

Adisorn said he had instructed investigators to work diligently to bring the culprits to justice.

"We are focussing our attention on witnesses and evidence submitted by the Scientific Crime Detection Division," he said.

Police, the Army and Bangkok Metropolitan Administration have stepped up security in the capital following the explosion. There are now more checkpoints, increased patrols and more security officers on duty.

A meeting today will focus on gathering intelligence, following a security meeting convened on Sunday shortly after the blast.

Bangkok Governor Apirak Kosayodhin said yesterday he would ask private entrepreneurs to install more security cameras.

"There should be more security cameras at department stores as well as skytrain and subway stations," he said.

Apirak said he planned to ask TOT Plc and True Corporation to remove little-used phone booths in the capital too.

The bomb on Saturday night exploded inside a phone booth just as the victim was getting in. He was slightly injured as it appeared the bomb was meant to frighten, not claim lives.

Apirak said he had instructed all district officers to carry out more weapons searches in risky areas, especially areas frequented by foreigners such as Khao San Road.

Metropolitan Police Division deputy spokesman Colonel Piyaphan Pingmuang said officers from his division and directors of all district offices in Bangkok would discuss ways to boost security, social order, co-operation between people and officials, as well as to enhance traffic flow.

"We will also have a workshop on May 23 to brainstorm clearer ideas and policies," he said.