Four militants killed in Egypt

At least four militants were killed Sunday while planting an explosive devise in Egypt's Sinai, a security source said.

"The four extremist Islamists were planting the bomb on Sheikh Zuweid international road to target a security check point at the entrance of the city," the source said.

The incident took place after some militants attacked an armoured vehicle with a rocket-propelled grenade in Arish city, which injured an army officer, Xinhua reported.

On Saturday, a military helicopter crashed in Sinai, killing five-man crew.

Security conditions have been deteriorating in Sinai since the ouster of Islamist president Mohamed Morsi by the army in July last year, as militants took the area as a stronghold for staging attacks against army and police officials.