Cairo: A roadside bomb killed three civilians Wednesday in the Sinai Peninsula where Egyptian forces are fighting an Islamist insurgency, police and medics said.

Militants regularly attack security forces in the region in ‘retaliation’ for a bloody crackdown on supporters of ousted Islamist president Mohammad Mursi.

Three passers-by were killed when the roadside bomb went off south of the town of Rafah, which borders the Palestinian Gaza Strip, a police officer said.

The area is a bastion of the militant group Sinai Province, formerly known as Ansar Beit Al Maqdis.

The organisation has pledged allegiance to Daesh, which has captured swathes of territory in Iraq and Syria.

Officials say hundreds of Egyptian policemen and soldiers have been killed in militant attacks, including in Cairo, since the army overthrew Mursi in 2013.

A police crackdown targeting Mursi supporters, meanwhile, has left more than 1,400 people dead and thousands imprisoned.

Hundreds have also been sentenced to death after speedy mass trials, which the United Nations says is “unprecedented in recent history”.