For the first time, sophisticated U.S. military surveillance drones capable of carrying missiles have begun patrolling waters off Somalia in hopes of stemming rising piracy.

Three ships have been seized in a week off Africa's lawless eastern coast and Vice Adm. Robert Moeller, the deputy commander for the U.S. Africa Command, said pirates continue to pose a significant challenge.

With the monsoon season now ended, there have been a rash of attacks as pirates return to the open seas. More than 130 crew members from seven ships are currently being held, including about 70 from the latest attacks.