The U.S. Navy has confirmed that one of its ships was involved in a rescue operation in the Mediterranean.

The U.S. Sixth Fleet, which is based in Naples, Italy, said in a brief statement to The Associated Press that the USNS Trenton on Tuesday "rendered assistance to mariners in distress that it encountered while conducting routine operations in the Mediterranean Sea."

It said 40 people were rescued and are being given food, water and medical care on board the ship. The Navy statement didn't say where the survivors would be taken but that "U.S. authorities are coordinating with our international partners to determine their ultimate disposition."

The incident was first reported by German migrant aid group Sea-Watch, which said 41 people were rescued and 12 bodies recovered during the operation.

A German migrant aid group earlier its ship is heading toward a shipwreck 20 miles (32 kilometers) off the coast of Libya in which 12 people are believed to have died.

The Sea-Watch group wrote on Twitter Tuesday that the wreck was reported "by an order of the U.S. Navy, which has rescued 41 people from the water and confirms 12 corpses."

Sea-Watch is one of several aid groups operating rescue ships in the Mediterranean. There were no immediate details on the wreck and its passengers.

Italy's new government this week refused to allow another charity group's rescue vessel to dock in a bid to force Europe to share the burden of unrelenting migrant arrivals.