Somali pirate groups Tuesday vowed to kill American and French crews of ships hijacked by them after US marines shot dead three of the four pirates holding a US captain hostage, local media reports said.

The threat came after a three-day hostage drama of Captain Richard Phillips, who was abducted after his ship Maersk Alabama was briefly taken by Somali pirates, ended with the killing of three pirates and capture of the fourth by US special forces.

"If they have started killing us, we (pirate groups) have decided to take revenge and kill any American or French crew or passenger members of ships we capture fishing in our seas," Jaama Siyad, a pirate spokesman told local Shabelle radio in Mogadishu.

Siyad said pirate gangs were in agreement that if any group hijack a ship with either a crew or a passenger from France or the US they would immediately "shot them in the head".

Two Somali pirates were killed and four others captured by French commandos in a rescue operation on a French yacht off Somalia. Four French passengers were rescued while another was killed in the shootout between the pirates and French troops.

The Somali government has welcomed the rescue operations of both French and American troops saying it was the right thing to do in such circumstances. The Somali government has always been opposed to the payment of ransoms to pirates saying it encourages more pirate activities in the Horn of Africa coast.

Somali pirates are holding several ships with a couple of hundred crew members but it is not clear if they include American or French nationals.

Somali pirates do not usually harm their captives in expectation of the hefty ransom payout often received following negotiations with foreign governments or ship owners.

Dozens of countries have their navy patrolling the pirate infested Somali waters and the Gulf of Aden to prevent hijackings of commercial ships plying the important waterway after the UN Security Council authorized member states to fight piracy and the armed robbery at seas off Somalia last year.??

(Xinhua News Agency April 14, 2009)