Two hostages have escaped a German cargo ship captured by Somali pirates off the Seychelles and are safely aboard a Danish navy vessel, a spokeswoman for the ship's Bremen-based owners said on Saturday.

The spokeswoman however would not confirm details of a report by German magazine Der Spiegel which said the two -- part of a 12-men crew -- escaped during a firefight on Wednesday in which two other crew and up to two pirates were killed.

"Currently two members of the crew are missing," CEO Niels Stolberg of Beluga Shipping said in a later e-mail exchange. "Two other seamen could be rescued yesterday, and they are safe and sound," he said, adding that no ransom had been demanded.

According to the Spiegel report, the deaths occurred after a Seychelles patrol boat opened fire on the pirates in an attempt to rescue the ship, named Beluga Nomination. Two crew escaped by jumping overboard in a life boat.

The ship was boarded last Saturday about 800 miles off the Seychelles, far from the areas where pirates mainly operate. But experts say the pirates' reach is growing as they increasingly use hijacked merchant vessels with hostage crews as giant motherships to attack shipping deeper in the Indian Ocean.