The United States Embassy says Ethiopian authorities have detained several foreign pilots, including Americans, who were participating in a trans-Africa air rally.

The Embassy issued a statement Thursday that it is working with Ethiopian officials to secure consular access to see the Americans, who are part of a larger group of pilots held by Ethiopian officials.

The Vintage Air Rally billed itself as a "flying rally across Africa, from Crete to Cape Town," for planes built in the early 20th century.

Wossenyelah Hunegnawm, the head of the Ethiopian Civil Aviation Authority, said the pilots entered Ethiopian airspace illegally Tuesday and are under investigation.

He said the pilots are in Gambella town in Western Ethiopia, where they landed their aircraft during their journey as part of the air event.