Two border patrol officers were killed and three other people were wounded early yesterday when a bomb exploded at a border checkpoint along Thailand's frontier with Malaysia, police said.

The blast went off at 8:05am at the Muno border checkpoint in Narathiwat province, police Lieutenant Colonel Ong-art Inthraraee told AFP .

The bomb detonated near a pier on the river that separates Thailand from Malaysia, killing two Thai border patrol officers instantly and injuring two other officers and a villager, he said.

More than 650 people have died in since an Islamic separatist insurgency broke out in southern Thailand in January 2004, in almost daily attacks that have targeted government officials as well as seemingly random villagers.

The blast came less than 12 hours after Thailand's respected Queen Sirikit made a rare nationally-televised appeal urging an end to the unrest in the mainly Muslim south.

Softer approach

Thailand's government, widely criticised for its heavy-handed tactics in countering the insurgency, has taken a softer approach in the last two months.

Prime Minister Thaksin Shinawatra named a National Reconciliation Commission charged with drafting a peace plan to end the insurgency.

The panel heard from hundreds of people on Saturday at a public forum in the southern town of Pattani, where residents urged authorities not to blame the region's entire population for the insurgent violence, the Bangkok Post reported.

The southern provinces along the Malaysian border are predominantly Muslim and ethnic Malay, unlike the rest of the Buddhist kingdom.

The region was once a separate kingdom, but was annexed by Thailand in 1902.