GENEVA — A Swiss shipping company says 12 crew members of a bulk carrier who were abducted by pirates more than five weeks ago near Nigeria have been released, as Polish authorities look into another possible hostage-taking off the West African country's coast.

Massoel Shipping says the seven Filipinos, a Slovenian, a Ukrainian, a Romanian, a Croatian and a Bosnian were freed late Saturday in Port Harcourt, Nigeria, and were in Switzerland on Monday before returning home.

The Geneva-based company said it would not provide details of the release "as to do so would only encourage further criminal acts of this kind."

Massoel said the ship carrying wheat was attacked Sept. 22 as it sailed from Lagos to Port Harcourt. The attackers apparently boarded using long ladders and cut razor wire on the deck to reach the bridge. Seven crew members were not captured.

Blake Sinclair, a spokesman for Massoel, said the crew members were "as well as can be expected, given the circumstances." He said details of their detention were not immediately available.

Separately Monday, Poland's Foreign Ministry said it was looking into the reported abduction of 11 crew members of a Liberian-flagged container ship, the Pomerenia Sky, off the Nigerian coast.

Privately owned Polish radio station RMF FM reported that eight Poles, two Filipinos and a Ukrainian were abducted Saturday following a suspected pirate attack as the vessel was arriving from Angola. The report did not specify the source of that information.