The Egyptian state news agency MENA says the Rafah border crossing with Gaza has been closed indefinitely, following an attack on a police station in Sinai in which 15 officers died.
The station guards a crossing near Egypt's border with Israel.
The agency reports that the attack was staged by Islamist militants who infiltrated from Gaza through tunnels.
An Israeli military spokesperson, Lieutenant-Colonel Avital Leibovich, says the gunmen hijacked two vehicles from the Egyptian outpost.
She says one of the vehicles exploded and the second was targeted by Israeli aircraft.