The rangers were ambushed while travelling in a pick-up truck on Monday in Pattani province.

On the same day, four died on their way to work in two separate gun attacks in Pattani, while a pair of men were killed in a drive-by shooting in neighbouring Yala province, police said.

Two vegetable vendors were also shot dead in Songkhla province, which had been relatively untouched by the violence until a number of attacks this year.

"Some militant groups don't want a peaceful solution so they look for an opportunity to terrorise people," southern army spokesman Colonel Pramote Prom-in told AFP on Tuesday.

"We're trying to find measures to prevent this kind of violence but still haven't succeeded," he added.