MOGADISHU, Somalia (AP) — Somali pirates who have been holding a hijacked ship for nearly two years killed a Syrian hostage crew member and wounded another to protest delayed ransom payment, a pirate leader said.

This is believed to be the first time Somali pirates have killed a hostage because of a delay in ransom.

Hassan Abdi, a pirate commander in Haradhere town, a key pirate centre, said Friday that the killing on Wednesday was a message to the owners of the ship MV Orna that was hijacked off Seychelles in 2010.

"The killing was a message to the owners of the ship who paid no heed to our ransom demands," Abdi said by telephone.

"More killings will follow if they continue to lie to us — we have lost patience with them. Two years is enough," he said angrily.

The MV Orna is a Panama-flagged, bulk cargo vessel owned by a company in the United Arab Emirates.

The pirates, operating along the Somali coastline of the Indian Ocean, were once were believed to be disgruntled and financially motivated Somali fishermen, angry that international trawlers were illegally fishing Somalia's waters. But now criminal gangs are dominating the piracy trade and they have become increasingly violent as international navies attempt to crackdown on their activities.

Somali pirates hijacked the MV Orna after firing rocket propelled grenades and small arms at the ship in December 2010, when it was about 400 miles northeast of the island nation of the Seychelles.

In May last year an undisclosed number of pirates and hostages were forced to abandon the Orna after a fire broke out, said Abdi. It is believed the fire was caused by an electrical problem in the ship's kitchen, he said.

The European Union Naval Force patrolling the Indian Ocean waters has not heard about the killing, said spokesperson Lieutenant Commander Jacqueline Sherriff.

Since, 2008, the EU has maintained a flotilla consisting of between five and 10 warships off the Horn of Africa to fight piracy. It is part of a larger international fleet that includes US, NATO, Russian and other warships. The EU taskforce also includes non-EU countries such as Norway, Croatia, Montenegro and Ukraine.

Pirate attacks off Somalia's coast plunged to 69 in the first six months this year from 163 a year earlier, according to the EU force. Somali pirates were able to seize 13 vessels, down from 21, according to piracy watchdog the International Maritime Bureau.