Islamic State (IS) ­militants launched a wide-scale coordinated assault on several military checkpoints in Egypt's North Sinai on Wednesday in which 50 people were killed, security sources said, the largest attack yet in the insurgency-hit province.

Egyptian army F-16 jets and Apache helicopters strafed the region that lies within the Sinai Peninsula, a strategic area located between Israel, the Gaza Strip and the Suez Canal.

It was the second high-­profile attack in Egypt this week. On Monday, the prosecutor-­general was killed in a car bombing in Cairo.

The attacks raise questions about the government's ability to contain a Sinai-based insurgency that has already killed hundreds of police and soldiers.

Egyptian IS affiliate, Sinai Province, claimed responsibility for the Sinai attacks in a Twitter statement.

The army had said five checkpoints were attacked by about 70 militants and that soldiers had destroyed three land-cruisers fitted with anti-aircraft guns. Without giving a breakdown, the army spokesperson said the death toll among soldiers and attackers had ­increased.

The militants have previously carried out some big attacks that have killed scores of security personnel, but in general they have focused on smaller-scale attacks.

Wednesday's incident marks the biggest onslaught yet.

Doctor Osama el-Sayed of El-Arish General Hospital in the provincial capital said 30 bodies had been brought in, "some of whom were wearing army fatigues."

Security sources said militants were surrounding a police station in the town of Sheikh Zuweid and had planted bombs around it to prevent forces from leaving.

They also said the militants had planted bombs along a road between Sheikh Zuweid and an army camp to prevent the movement of any army supplies or reinforcements.

The militants managed to seize two armored vehicles and boxes filled with weapons and ammunition, the sources said.

The insurgency based in the Sinai is seeking to topple the Cairo government and has managed to defy one of the toughest security crackdowns in Egypt's history.