The United Nations has warned its staff to be vigilant against possible attacks in Bangkok after a separatist group had vowed to stage revenge in the capital for thedeaths of 85 Muslim protesters in the deep South last week.

The threat "cannot be dismissed or be taken lightly", the United Nations said in an e-mail message to more than 1,000 staff in Thailand.

"It is entirely possible that an attack is being planned against a soft target in Bangkok," The Nation newspaper quoted thetwo-page note from a UN chief security officer as saying on Thursday.

The officer said security in Bangkok malls and public transportation was "designed to combat petty crime and would not be that effective in preventing an attack."

The mail suggested UN staff be cautious when moving about the city and be aware of what happened around them.

On Oct. 25, seven protesters died during clashes with security forces in the southern Narathiwat province, and another 78 were crushed later in crowded military trucks after they were detained.

Also in the south, a 62-year-old trader was slashed to death Tuesday evening in a rubber plantation in Yala's Betong district.

Local police said on Wednesday that the man's neck was almost completely severed and his body bore more than 10 knife injuries.

The killing might be related to the violence that has reigned the southern region since the beginning of the year, they added.

Source: Xinhua