Cairo: Three suspected militants were killed in a car explosion in the October 6 suburb of the Egyptian capital on Tuesday, police said.

The blast came a day after the top prosecutor was killed in a car bombing in Cairo, prompting President Abdel Fattah Al Sisi to pledge tough new laws to fight militants.

Police officials said they believed the blast occurred when explosives the militants had been transporting went off accidentally.

It would not be the first time suspected militants in Egypt have accidentally blown themselves up while making or transporting explosives.

Militants have killed hundreds of policemen and soldiers since the army overthrew Islamist president Mohamed Morsi in July 2013.

Police have been on heightened alert ahead of the second anniversary of his overthrow on Friday.