CAIRO: Gunmen attacked a security checkpoint in a city north of Cairo on Monday and killed three policemen, the Interior Ministry said, the latest sign that militants who are waging an insurgency in the Sinai Peninsula may be spreading their campaign to mainland Egypt.

There was no immediate claim of responsibility for the attack in the city of Mansoura, but such attacks are typical for the militants opposed to Egypt’s military-backed government.

Meanwhile, an Egyptian Kung Fu gold medalist has been suspended because he displayed a Muslim Brotherhood symbol showing support for ousted President Muhammad Mursi during a tournament in Russia.

Egyptian security officials confirm that the player Mohammed Youssef flew to Cairo Monday from Moscow after being sent home early.

Al-Ahram’s website posted a photo of Youssef wearing a T-shirt emblazoned with a picture of an open palm with four yellow fingers — the symbol representing a pro-Mursi protest camp violently cleared by security forces in August.

Youssef also held his gold medal with his right hand while punching the air with a clenched left fist during the medal ceremony.