A German merchant ship has been hijacked by pirates off the coast of Nigeria, a German radio station reported Tuesday. The Cape Bird, a 180-metre chemicals tanker, was taken over Saturday night. It sent a distress call before the pirates gained control, the public broadcaster NDR 90,3 said. It quoted Carsten Sommerhage of Columbia Shipmanagement, the shipping line that operates the vessel, as saying that the crew of 20 had been unharmed several hours after the seizure, which was not initially made public. No other details were immediately available on the pirates\'\' demands.