FIVE SOMALI MEN HAVE been sentenced to life in prison for hijacking a US Navy ship – the harshest sentence imposed on maritime pirates by a US court to date.

The five men were convicted in November 2010 on federal piracy charges after confessing to an attack on the USS Nicholas in April 2010.

Piracy carries a mandatory life sentence in the US, and the men also received additional 80-year sentences for firearm and piracy-related charges, the AFP says.

The Christian Science Monitor reported that the naval vessel had captured the five pirates after a dramatic exchange of fire near the Seychelles in the Indian Ocean.

The US trial relied on rarely-used 19th century maritime laws and is the first piracy case tried in the US since the Civil War, according to Al Jazeera.

Maritime piracy is estimated to cost the global economy up to €8.97bn annually and last year a record number of people were taken hostage by pirates, according to figures compiled by piracy monitoring group, the International Maritime Bureau.

In early January, a Danish family including three children were kidnapped by pirates from their yacht. They had managed to send a distressed signal during the attack, but were taken hostage before other ships could come to their rescue.

An attempt to rescue them from their captors was foiled last week, after which a pirate warned they would be killed if further rescue attempts were made.