Details were not available from the ministry but broadcaster Channel News Asia reported that Lieutenant Chua Chue Teng, a 23-year-old trainee officer, is alleged to have navigated the RSS Courageous in an unsafe manner into the path of the cargo vessel ANL Indonesia on January 3.

Lt. Ng Keng Yong, the 27-year-old officer of the watch, is alleged to have failed to supervise Lt. Chua, and both were charged with causing the deaths of the servicewomen, the report said.

It was the worst accident in the history of the city-state's navy.

Both officers are out on bail of 10,000 Singapore dollars (5,800 US), the report said. Their cases will reopen on July 8.

The charges were filed after an official investigation which ended in April concluded that Lt. Ng made "errors of judgement" that led their anti-submarine vessel into the path of the Dutch-owned ANL Indonesia.

Lt. Chua was in control of the vessel at the time of the collision, but was under the direct supervision of Ng who approved the trainee's instructions to change course.

As the two vessels headed towards each other in the eastern Singapore Straits near Pedra Branca island, the trainee ordered the 452-tonne RSS Courageous to change course to port, or the left side.

Ng, the officer of the watch, approved the change despite knowing that the move was against maritime regulations, investigators said.

Such regulations state that when two vessels are heading towards a possible collision, each must change course to starboard, or the right side, so that they would pass each other on the left side.

The 51,938-tonne ANL Indonesia took the correct action by moving starboard, the investigators said.

WAR.WIRE