Four Thai soldiers were killed when a powerful roadside bomb went off on Wednesday in Thailand’s unrest-plagued south, police said.

Four Thai soldiers were killed when a powerful roadside bomb went off on Wednesday in Thailand's unrest-plagued south, police said.

Twelve other soldiers were wounded and six of them remain in a critical condition, AFP reported.

The 50kg bomb, hidden in a gas canister, was detonated by a mobile phone device at around midday as an army truck approached.

Police in nearby Yala province said two Muslim villagers had been shot dead on Tuesday.