Image caption Successful pirate attacks have decreased in recent years

A court in Japan has sentenced an African man to 11 years in jail for the attempted hijack of a Japanese tanker.

He was one of four men who attempted to hijack the tanker just off the coast of Oman in 2011. The other men have already been sentenced.

They were captured by US Navy personnel and handed over to Japan's coastguard.

Recent years have seen a reduction in piracy off the Horn of Africa, with pirates deterred by an international deployment of warships in the area.

The 21-year-old, believed to be Somali, was a juvenile under Japanese law at the time of the incident, reports said.

The men, who were armed with submachine guns, tried to seize the Mitsui OSK Lines tanker.

Japan applied it's new anti-piracy law for the first time and transported the men to Tokyo to face trial.

The defendant, not named because of his age at the time the crime was committed, pleaded not guilty,

He claimed that the small boat he was aboard was adrift and he had asked for help from the tanker, the Jiji Press agency said.

However, testimonies from the other men led the judge to believe he was part of the attempted hijacking.

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