The Thai troops are thought to have links to a Myanmar drug kingpin.
The soldiers surrendered on Friday in northern Chiang Rai province, Lieutenant General Wut Liptapanlop told AFP, declining to give more details because the investigation was ongoing.
National police chief General Priewpan Damapong promised a full investigation into the deadly raid on two Chinese vessels on October 5, saying the military was fully cooperating.
“Police will prosecute all nine soldiers,” he told reporters. “Their actions have nothing to do with the Thai army.”
China summoned diplomatic envoys from Thailand, Laos and Myanmar in the wake of the attack and asked them to speed up investigations.
Beijing also sent patrol boats down the Mekong to escort 164 stranded Chinese sailors and 28 cargo ships back home.
BANGKOK, October 11, 2011 – Thai authorities on Tuesday said the bodies of 13 people had been recovered after a raid last week on two Chinese cargo boats on the Mekong thought to have been carried out by a notorious drug gang.