Six Somali pirates have been jailed for 16 and a half years each, a court in Spain ruled.

On Wednesday (February 4), the criminals were found guilty for attacking the Spanish tuna trawler Izurdia using AK-47 assault rifles off the coast of Somalia on October 10, 2012.

The pirates were caught by a Dutch navy vessel taking part in the EU Atalanta.

They have been kept in a jail in Spain since November 2012.

In the court's ruling it was said that the six men were members of a criminal group.

“They formed an assault cell or organised pirate group with material to board and kidnap commercial boats that sailed in the Indian Ocean off the coast of Somalia,” was further said.

The pirates were found to be part of a Harare-based (capital of Zimbabwe) criminal group.