MOGADISHU: An Indian warship destroyed a pirate "mother vessel" in the Gulf of Aden, the navy said Wednesday, as bandits demanded a ransom for a Saudi super-tanker seized in the most daring sea raid yet.

The Indian frigate INS Tabar, one of dozens of warships from several countries protecting shipping lanes in the area, attacked the Somali pirate ship late Tuesday after coming under fire, navy spokesman Nirad Sinha said.

The incident came as shipping groups reported a new surge in hijackings off Somalia and the International Maritime Bureau said pirates based in the lawless African nation were "out of control".

"The INS Tabar closed in on the mother vessel and asked her to stop for investigation," the New Delhi navy spokesman said.

"But on repeated calls, the vessel's threatening response was that she would blow up the naval warship if it approached."

An exchange of fire ensued, causing explosions and the navy ship then used heavy guns. "From what we see in photographs the pirate vessel is completely destroyed," a senior officer said on condition he not be named.

It was the first time a mother ship had been destroyed, in the most significant blow to pirates to date.

The piracy crisis has grown since the weekend capture of the super-tanker Sirius Star. The huge vessel was carrying a full load of two million barrels of oil worth around 100 million dollars.