A Dutch court has sentenced five Somali men to up to seven years in prison on piracy charges.

A judge in the Netherlands imposed the sentences on Friday.

The suspects are all in their twenties. Two of them hijacked the South African yacht Choizil off the coast of Tanzania in November. Authorities say two people taken hostage during that incident have not been found.

Somali pirates have hijacked dozens of ships and made hundreds of millions of dollars from ransom payments in the past few years.

The pirates continue to terrorize shipping in the Indian Ocean and Arabian Seas despite international naval patrols.