Prosecutors are considering indicting two officers in the Maritime Self-Defense Force over the collision last year between a destroyer and a small fishing boat on suspicion of professional negligence resulting in the deaths of two fishermen, according to sources.

They are Lt. Cmdr. Keitaro Ushirogata, 36, whose duty shift ended just before the 7,750-ton Atago collided with the 7.3-ton Seiroku Maru in the early hours of Feb. 19, 2008, and Lt. Cmdr. Tomohisa Nagaiwa, 35, who had just come on duty when the accident took place off the coast of Chiba Prefecture.

It is rare to indict a crew member who was not actually operating the ship when it had a collision. The focus of a criminal trial would be the responsibility of the individual officers aboard the warship.

The Yokohama District Prosecutor's Office is planning to discuss the matter soon with the Supreme Public Prosecutor's Office.

If they go ahead, the indictments would come by the end of this month, the sources said. The prosecutors are eyeing indictments without arrest.

In a decision issued in January, the Yokohama Marine Accident Tribunal blamed the Atago for the collision.

Haruo Kichisei, 58, and his 23-year-old son, Tetsuhiro, on the Seitoku Maru went missing and were later declared dead.

The marine accident tribunal determined that Nagaiwa's inadequate observation was the cause of the collision, but it did not recognize any causal relationship between the collision and Ushirogata's actions.

The prosecutors, however, believe both lieutenant commanders visually confirmed the presence of the fishing boat but neglected to follow up with adequate observations or take appropriate actions to avoid a collision, the sources said.

The Japan Coast Guard and the prosecutors said that when Ushirogata handed over duties to Nagaiwa, he erred in saying there was no danger of a collision.