Story highlights A car bomb apparently targeting the interior minister's motorcade explodes in Cairo

Four security personnel were injured in the blast, a state news agency says

Security services are investigating; it's not yet clear who was behind the attack

The interior minister, Mohammed Ibrahim, is safe, state-run Al-Ahram reports

A car bomb apparently targeting the Egyptian interior minister's motorcade exploded in eastern Cairo Thursday, leaving four people injured, state media reported.

The interior minister, Mohammed Ibrahim, is safe, according to the state-run Al-Ahram newspaper.

Al-Ahram said no one was killed in the blast near the minister's residence in Nasr City.

Egyptian state news agency EgyNews said four security personnel were injured, with one policeman having a leg amputated as a result of his injuries.

An Interior Ministry statement said the explosion caused injuries to security guards and some bystanders.

It occurred about 10:30 a.m. as the minister's convoy passed through Mostafa El Nahas Street in Nasr City, it said. Security agencies are investigating, the ministry added.

It's not yet clear who was behind the attack. Official news agency MENA cited a security source as saying the bomb was remotely detonated.

Cairo has witnessed wide unrest on its streets since former President Mohamed Morsy was ousted in July and an interim administration was installed by the military.

A crackdown last month by Egyptian authorities on Morsy supporters left hundreds of people dead.