Egypt hits suspected militants smuggling arms from Libya

Army spokesman Tamer el-Rifai said in a statement that the air strikes on the western border were part of operations to track down "terrorists" who killed 16 policemen in a shootout in the region last week.

Thirteen other policemen were wounded in clashes with Islamist militants during Friday's attack on the road between Cairo and the oasis of Bahariya in the Western Desert, said the defence ministry.

Security forces were sent to the area southwest of Cairo acting on information that militants there were "hiding, training, and preparing to carry out terrorist operations", according to the ministry.

The air force said its warplanes raided the border area, "foiling a new infiltration attempt" and destroying eight vehicles that were carrying "large quantities of weapons, ammunition and explosive material".

A military statement said those travelling inside the vehicles were killed during the operation, without specifying how many.

Since the army in 2013 removed elected Islamist president Mohamed Morsi of the Muslim Brotherhood, extremist groups have stepped up attacks on the military and police in Egypt.

Security forces are fighting the Egyptian branch of the Islamic State (IS) group, which has increased its attacks in the north of the Sinai peninsula more than 500 kilometres (300 miles) away from the latest violence.

Authorities have repeatedly said that jihadists active in Egypt were trained in Libya.

The air forces struck jihadist targets in Libya in May, hours after IS claimed responsibility for an attack that targeted Coptic Christians on their way to a monastery south of Cairo.

In February 2015, the air force also raided jihadist positions in Libya after IS posted a video on the internet of the gruesome beheading on a Libyan beach of 21 Christians, all but one of them from Egypt.

Libya has been rocked by chaos since the 2011 fall and killing of longtime dictator Moamer Kadhafi, with rival administrations, and militias, vying for power.

Jihadists, arms dealers and people traffickers have since taken advantage of the chaos to gain a foothold in the oil-rich North African country.