Cairo: Gunmen killed three policemen in Egypt’s volatile Sinai Peninsula on Monday, security sources said, and an Islamist militant group released a video of an earlier drive-by shooting of an army colonel.

Security sources confirmed that gunmen had killed the colonel, identified as Mohammad Al Komi, on August 14 on a desert highway near the Suez Canal city of Ismailia.

The Sinai has become a major security headache for the Egyptian authorities since the army overthrew elected President Mohammad Mursi of the Muslim Brotherhood in July.

Almost daily attacks by Al Qaida-inspired militants have killed more than 100 members of the security forces since Mursi’s ouster, the army spokesman said on September 15.

Instability in the Sinai worries Western governments because the region borders Israel and flanks the strategic Suez Canal, the quickest sea route between Asia and Europe.

Hard to police

The Sinai is hard to police partly because it borders the Gaza Strip, which is run by the Islamist group Hamas, an offshoot of the Muslim Brotherhood.

The Egyptian army says Gaza-based militants take part in attacks over the border and accuses Hamas of doing too little to secure the area, allegations it denies.

In the latest violence, gunmen killed two policemen as they were eating breakfast outside a police station in the city of Al Arish in North Sinai. In a separate attack, a police officer walking in the city was shot in the head and chest and killed.

Gunmen also killed a civilian in the nearby town of Shaikh Zuwaid.

Militants expanded into a security vacuum left by the 2011 fall of autocrat Hosni Mubarak, but attacks have risen sharply since Mursi’s overthrow. Attacks elsewhere in Egypt have raised concerns that an Islamist insurgency could spread beyond Sinai.

Failed suicide bombing

The Sinai-based Ansar Bayt Al Maqdis group claimed responsibility for a failed suicide bombing in Cairo on the interior minister this month.

Sinai militants, who are armed with assault rifles, rocket-propelled grenades, explosives and Grad missiles, have posted online footage of some of their attacks — a common practice among Al Qaida-linked groups trying to motivate fighters and intimidate their enemies.

In one video posted on a jihadi website on Monday, a militant group calling itself ‘Al Nusra Battalion’ shows what it says was the attack on Colonel Al Komi.

A man with an assault rifle is filmed aiming from a car window and shooting at another vehicle driving on a desert road. “Targeting the criminal apostates and liquidating them,” a caption reads.

A picture of the uniformed officer flashes on the screen next to the car seen in the drive-by shooting, a back window pocked with bullet holes and blood running down the driver’s door.

The video says Al Nusra Battalion is a unit of ‘Al Firqan Brigade’, a militant group that took responsibility for an attack this month on a container ship in the Suez Canal.

The army, which has been operating with the police in Sinai, said on August 7 that it had killed 60 militants in the month since Mursi’s overthrow.

“There are great security successes on the ground in Sinai now,” Interior Ministry spokesman Hany Abdul Latif said when asked about the Al Nusra Battalion video. “We’ve arrested dangerous elements and confiscated heavy weapons, and we have a large degree of control.”