Police stand guard outside a morgue in Cairo, Egypt, ahead of the arrival of bodies of Russian plane crash victims Saturday, Oct. 31, 2015.

Masked gunmen on a motorcycle shot dead four Egyptian policemen south of Cairo on Saturday, the interior ministry said.

The gunmen opened fire on a police vehicle, killing those inside, in an area between the famed Giza pyramids west of Cairo and the Saqarra pyramids to the south, the ministry said in a statement.

The attackers’ affiliation was not immediately clear.

Islamist militants have killed scores of policemen and soldiers, mostly in the Sinai Peninsula, since the army overthrew Islamist president Mohammed Mursi in 2013.

Attacks have also targeted policemen and government buildings in the capital, several of them claimed by an ISIS group affiliate.

The extremists often claim that their attacks are retaliation for a police crackdown on Islamist protesters, which has killed hundreds and left thousands in prison since Mursi’s overthrow.

Egyptian military helicopter crashes

In a separate story, Egypt’s military says one of its helicopters has crashed after a “sudden technical failure,” injuring an undisclosed number of crew members.

A statement on Saturday’s crash said the helicopter was on a reconnaissance mission northeast of Cairo in the Ismailia province. It did not say how many crew members were injured or how badly they were hurt.

The Egyptian military has struggled to quell the ISIS jihadists in Sinai, who claimed responsibility for bombing a Russian passenger plane on Oct. 31 over the peninsula, killing all 224 people on board.

But the militants have suffered more losses in Cairo, with police repeatedly killing or arresting cells in the capital.

The interior ministry announced earlier this month the killing of a top ISIS operative in Cairo suspected of involvement in the abduction and execution of a Croatian oil worker, and the bombing of the Italian consulate.

Ashraf Ali Ali Hassanein al-Gharabli died in a hail of bullets after he opened fire on policemen who tried to arrest him in the north of the capital, the ministry had said.

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