Four Thai soldiers were killed and at least a dozen others wounded when a roadside bomb went off in the south of Thailand.
The 50kg bomb was hidden in a gas canister and detonated by a mobile phone around midday on Wednesday as an army truck approached, a police officer in the Kha Pho district of Pattani province told AFP news agency.
"Sixteen soldiers were in the army truck. They were being reshuffled for rest and recreation," the officer said.
Four of the victims died at the local hospital and six other soldiers remain in critical condition.
Southern Thailand has been plagued with unrest in recent years.
More than 5,500 people have been killed in this region since 2004, with rebel groups blamed for near-daily bombings and shootings.
Security personnel, those connected with the government and Muslims thought to be collaborating with the authorities are regular targets.
Thailand held its first official peace talks with southern armed groups but no significant breakthroughs were made.