Somalia ? Somali pirates said Tuesday they celebrated a Muslim holiday aboard a hijacked freighter and denied reports that three comrades were killed in a shootout on the vessel, which is being closely watched by a half-dozen U.S. warships.

The hijacking of the MV Faina – laden with 33 Soviet-made T-72 tanks, rifles and heavy weapons that U.S. defense officials have said included rocket launchers – was the highest-profile act of piracy in the dangerous waters this year. The U.S. Navy has said it wants to keep the arms out of the hands of militants linked to al-Qaida in impoverished Somalia, a key battleground in the war on terrorism.

The pirates are demanding $20 million in ransom for the ship, which they boarded Thursday in the Indian Ocean off the Somali coast. There was a crew of 21 Russians and Ukrainians aboard, but the captain later died.