Yemeni navy and coast guard forces killed two pirates and injured three in a clash after Somali pirates seized a Yemeni oil tanker in the Gulf of Aden on Sunday, coast guard sources said.
The sources told DPA that two navy ships were sent to aid coast guards gunboats involved in a gunfight with the pirates.
"Two pirates were killed and three others injured in the fighting so far," said one source, adding that several Yemeni soldiers were injured.
A government official said the tanker, Qana, was empty of cargo when the pirates attacked it off the Yemeni coast earlier in the day.
He said the vessel was sailing from the Arabian Sea Yemeni port of Nashtoon to the southern port city of Aden when the pirates hijacked it.
Separately, Somali pirates Sunday freed a Yemeni tanker ship carrying more than 2,000 tonnes of diesel they held since Jan 3, Yemeni officials said. Fifteen crew members were also released, the officials said.
The release of the vessel, Sea Princess II, was secured through negotiations, the officials said, refusing to say whether a ransom was paid.
The tanker was en route from the Gulf of Aden to Nashtoon when the pirates attacked it and diverted it to the Somali coast.
The issue of piracy in the waters off Somalia, generally-recognised as a failed state, have created an international crisis for shipping, with the US navy and warships from EU countries now attempting to patrol the seas off the Horn of Africa.