Nine suspected army men deny killing Chinese sailors and want to be exonerated from the charges, Thai Army Chief Prayuth Chanocha said on Thursday, calling for "justice" for his subordinates as the investigation is still underway.

Prayuth said that as the army men were doubted so he ordered the Third Army Region to bring those them to report to the police so that they could have the chance to show their sincerity but it should not be misinterpreted as surrender.

"I would like to ask support for soldiers. They should have an opportunity to clarify themselves," he said.

"Ninety percent of my subordinates are good guys. Please don't prejudge them for committing crimes. It's not that easy to kill people even if their supervisors ask them to do so," said Prayuth.

Chalerm Ubumrung, Thai deputy Prime Minister in charge of security, said on Tuesday that investigators have gathered sufficient evidence in connection with the slaughter of Chinese sailors and truth will be clear within this week.

Two cargo ships, Huaping and Yu Xing 8, were attacked on Oct. 5 on Mekong River near the golden triangle area and 13 Chinese sailors were killed.

Nine army men, reportedly including one major and one lieutenant, from the Third Army Region guarding Thailand's northern border were identified as suspects last Friday by Thai police chief Priewpan Damapong.

But the group have denied two charges, murder and tampering of evidence, pressed by the police.