Eight plainclothes police officers have been gunned down after unidentified attackers unleashed a volley of bullets on their vehicle in Helwan, just south of Cairo, the Egyptian Interior Ministry has said. After getting out of a pick-up truck, four gunmen stopped the police vehicle and opened fire on it with automatic rifles.

A lieutenant and seven other lower ranking officers were among the dead. It is not yet clear who was behind the deadly attack, but a group called Popular Resistance claimed responsibility on its Facebook page. It said the assault was in retaliation to a bloody 2013 clampdown on the Muslim Brotherhood to avenge the "martyrs" who were killed.

Interior Minister Magdy Abdel-Ghaffar said that investigations into the killings will take place and praised what he described as the "heroes of the police martyrs who sacrificed their lives to preserve the security of the homeland and the people". The assailants, who were wearing masks according to Reuters, fled the scene after shooting the officers dead.

Terrorists from the Islamic State's (Isis) Egyptian branch, Sinai Province, have killed hundreds of soldiers and police since former president Mohammed Morsi was overthrown in July 2013. In March, at least 13 police officers were killed when militants opened fire with a mortar round at a security checkpoint in the city of Arish. The attack was claimed by Isis (Daesh) and confirmed by Egyptian state media.

While the worst atrocities have taken place in Sinai, extremists have also targeted the Egyptian capital, Cairo and other cities with bombs as well as hit-and-run attacks on police. In this instance, authorities believe automatic weapons were used based on the casings found at the scene.

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