Pattani, Thailand - Suspected separatists exploded a bomb outside a traditional massage parlour in Thailand's violence-wracked city of Narathiwat, injuring 19 people, officials said Sunday.

The explosive was detonated Saturday night shortly after gunmen shot at a nearby karaoke bar, injuring two women and drawing soldiers to inspect the scene.

The bomb planted in a parked car in Narathiwat, 750 kilometres south of Bangkok, exploded shortly after the soldiers arrived.

Although no soldiers were harmed, the explosion injured 19 civilians and destroyed 12 cars.

A similar car bomb went off in Yala on February 13, which injured 17 people and destroyed a block of shophouses.

“These attacks aim at scaring the local populations so they will stop cooperating with Thai authorities,” said Colonel Banphut Phonpian, spokesman for the southern office of the Internal Security Operations Command.

The New York-based Human Rights Watch last week condemned a surge in violent attacks by separatist Muslim insurgents on civilian targets this year in Thailand's troubled southern provinces.

Since January, a series of shootings and bombings perpetrated by insurgents have claimed more than a dozen lives.

“There is no excuse for indiscriminate or deliberate attacks against civilians,” said Brad Adams, Asia director at Human Rights Watch. “The leaders of separatist insurgent groups need to rethink their tactics, which are abhorrent, illegal, and completely unjustifiable.”

Thailand's majority-Muslim southern provinces of Narathiwat, Pattani and Yala have been a hotbed for violence since January 2004, when a long-simmering separatist movement took a more militant turn.

About 4,370 people have died in the conflict over the past seven years, 90 per cent of them civilians, Human Rights Watch said.

About 80 per cent of the 2 million people living in the three provinces are Muslims, making it the only majority Muslim region in predominantly Buddhist Thailand. An estimated 300,000 Buddhists have left the region since in 2004.

The region was an independent sultanate until Bangkok conquered it about 200 years ago. The local population, which shares greater cultural, linguistic and religious similarities with neighbouring Malaysia, has never wholly submitted to rule by the central government. - Sapa-dpa