An 18-year-old Somali accused of trying to hijack an oil tanker operated by a Japanese firm pleaded guilty Monday but denied playing a key role in the attack.

The defendant, whose name is being withheld because he is a minor, said during the lay judge trial at the Tokyo District Court that he only abetted the other three hijackers and did not fire any weapons during the raid off the eastern coast of Africa.

"I am not a pirate," he told the court through an interpreter.