Pirates from Somalia who hijacked a Chinese bulk carrier in the Indian Ocean threatened on Tuesday to execute its 25 Chinese crew members if any rescue operation was attempted.

The bulk carrier, which the pirates say is loaded with fuel, was seized on Monday 550 nautical miles northeast of the Seychelles and 700 nautical miles east of the Horn of Africa.

'We tell China not to endanger the lives of their people with any rescue operation,' Hassan, an associate of the gang, told Reuters by phone from the pirate stronghold Haradheere.

'If they try that we will execute the whole crew ... we tell them to change their mind regarding any rescue, otherwise they will regret it. We know what they are planning to do.'    

Chinese Foreign Ministry spokesman Ma Zhaoxu said earlier in Beijing that his government had 'actively started rescue operations' for the ship.

On Monday the European Union's counter-piracy force said an EU maritime patrol aircraft had located the vessel and counted at least four pirates on the deck. It was heading for Somalia.-Reuters