An Egyptian militant group said it had carried out an attack on an Egyptian police convoy in Cairo that killed three officers and wounded five.

The interior ministry said "armed elements riding in two vehicles" had approached a moving convoy near the main ring road around Cairo last night.

The Hasm group later announced on social media that it had "succeeded in eliminating a security patrol belonging to the interior ministry's militias."

The convoy was going through a roundabout on the main ring road around the capital when the gunmen attacked.

Police returned fire and attempted "to apprehend the perpetrators," the ministry said.

The government says Hasm is linked to the outlawed Muslim Brotherhood movement of deposed Islamist president Mohammed Mursi.

The secretive group has previously claimed responsibility for deadly attacks against security forces as well as assassination attempts targeting a pro-government Muslim cleric and Egypt's deputy prosecutor general.

Egypt is fighting a long-running insurgency by a local affiliate of the so-called Islamic State group in North Sinai province.

Following deadly church bombings last month, President Abdel Fattah al-Sisi declared a three-month state of emergency on 10 April.

IS said it was behind the bombings in Tanta and Alexandria on 9 April that killed 45 people.

The military has killed several of the group's top leaders, but the extremists have expanded their attacks from Sinai to other parts of Egypt, including Cairo.