Separated twins Benjamin and Patrick Binder returned to West Germany Thursday, seven months after an operation in the United States separated their skulls and circulatory systems.

The twins arrived at Frankfurt airport Thursday morning on a Lufthansa flight from Washington, D.C., Lufthansa spokesman Richard Gessner said.

He said the twins were immediately taken by a private jet to an undisclosed destination in southern West Germany. Gessner said he did not know who had arranged for the private jet.

The boys, now 14 months old, were released from Johns Hopkins Hospital on Wednesday. Their parents, Theresia and Josef Binder, accompanied them on the flight.