An African man has been jailed for over ten years for the attempted hijack of a Japanese tanker off the coast of Oman in 2011.

The Tokyo District Court on Friday convicted the 21-year-old Somali national to 11 years for piracy, reports The Japan Times.

He was one of the four men who tried to seize the Japan-operated Mitsui OSK Lines tanker but was a juvenile under Japanese law at the time of the incident.

He pleaded not guilty after claiming that the small boat he was aboard was adrift and he had asked for help from the Japanese vessel, according to Jiji Press agency.

Presiding Judge Katsunori Ono said the defendant’s claim “completely contradicted” the testimonies of the other Somali defendants.

Two other men were earlier sentenced to 10 years, while another man, also a juvenile at the time, was given a sentence of five to nine years.

The men, armed with submachine guns, were captured by US Navy personnel and handed over to Japan’s coastguard.

Japan applied its new anti-piracy law for the first time and transported the four men to Tokyo to face trial for the attempted attack, reports BBC.