Two people were killed Thursday when assailants threw a bomb at the entrance of a youth leisure centre on the outskirts of Cairo.

Two people were killed Thursday when assailants threw a bomb at the entrance of a youth leisure centre on the outskirts of Cairo, Egyptian police said.

Police investigators could not confirm whether it was a criminal act or part of a bombing campaign by militants since the army's ouster of former Muslim Brotherhood president Mohammad Mursi in July 2013.

"Assailants threw a crude bomb at the guard post of a youth leisure center" in the impoverished Nahia neighborhood on the outskirts of Cairo shortly after dawn, a police officer told AFP.

The guard and a man sitting with him were killed, he added. Another police officer confirmed the toll.

Since the military ousted Mursi, militants have set off small bombs almost every day in Cairo and other cities, mostly targeting police and soldiers and often only causing minor damage.

More sophisticated attacks have killed scores of security personnel mainly in the restive Sinai Peninsula where security forces are battling an insurgency spearheaded by the Egyptian branch of the so-called 'Islamic State od Iraq and the Levant' (ISIL) takfiri group, Ansar Beit al-Maqdis.

The militant group says its attacks are in retaliation for the brutal government crackdown against Mursi supporters that has left hundreds dead and thousands jailed.

The group also wants to establish a province of the "caliphate" that ISIL has declared in parts of Syria and Iraq which it has overrun.