A Buddhist couple were gunned down in a drive-by shooting on Saturday morning by suspected militants, police said, the latest bout of violence in Thailand's Muslim-majority restive south.

Thailand's three southernmost provinces have since 2004 been plagued by conflict between ethnic Malay Muslim rebels agitating for greater autonomy and the Buddhist-majority Thai state, which annexed the region about a century ago.

Around 7,000 people have been killed in the violence, mostly civilians from both the Muslim and Buddhist communities.

The latest incident came in Narathiwat province's Ra-ngae district, the site of previous skirmishes and bombings as rebels and security forces wrestle for control of the area.

Paisal Jungsakul, 65, and his wife Sumol, 58 -- who ran a small restaurant -- were returning home from the market by motorcycle when they were shot dead on a remote road, said a police commander.

"Police suspect the killing was the work of a group of militants who operate in that area... based on the pattern of the attack," Major General Dussadee Choosangkij told AFP.

"The group uses the same weapons," he said.

The suspects also stole the couple's motorcycle, and authorities fear that it could be used in another bomb attack, Dussadee said, adding that an alert has been issued for the stolen bike.

The shooting comes more than a week after the end of Ramadan, the Muslim holy month which typically sees an uptick in violence in the region.

Last month, a motorcycle bomb was detonated at a crowded market in neighboring Pattani province, killing two civilians and wounding four military rangers.

Army officials believed it was in retaliation for the death of a fugitive suspected rebel leader in bordering Yala province, who was shot dead as authorities surrounded his house.

Peace talks have been inconclusive despite an intensification of army operations in the border zone with Malaysia.