WASHINGTON (AP) — Passengers at some overseas airports that offer U.S.-bound flights will soon be required to power on their electronic devices in order to board their flights — a measure intended to enhance aviation security at a time when intelligence officials are concerned about hidden explosives, a counterterrorism official said.

American intelligence officials have been concerned about new al-Qaida efforts to produce a bomb that would go undetected through airport security. There is no indication that such a bomb has been created or that there’s a specific threat to the U.S., but intelligence has suggested that al-Qaida and like-minded groups are focused on perfecting an explosive that could be hidden in shoes, electronics or cosmetics, said the official who spoke on condition of anonymity because the official was not authorized to publicly discuss the matter.