Ajnad Misr, a jihadist militant group operating in Egypt, has claimed responsibility for a bomb that exploded at Helwan University on Thursday, injuring four policemen.
The group said in a statement published on its Twitter account and circulated on jihadist sites that the attack was a "quick reply to the policemen [targeting] university youths."
Egyptian universities have been the scene of unrest since the start of the new academic year, with recurrent clashes occurring between police and students protesting against the government.
Dozens have been arrested or expelled and one student died from injuries acquired during clashes in Alexandria.
In its statement, Ajnad Misr said the attack was not "adequate for [police] crimes."
A Cairo court banned the group in May, declaring it a terrorist organisation.
The group has claimed responsibility for previous attacks on policemen at universities, including an attack in October outside Cairo University that injured six policemen and four civilians.
It also claimed responsibility for planting bombs near Ittihadiya presidential palace on 30 June which killed two police officers, in addition to a blast outside the foreign ministry in Cairo in September that also killed two policemen.
Egyptian authorities are battling mounting militant violence which is concentrated in the Sinai Peninsula but has also spilled over into Delta governorates and the capital.
Militant attacks have killed hundreds of police and army troops, while civilians have also died in the violence.
Other jihadist groups operating in Egypt include Ansar Beit Al-Maqdis, which operates mainly in Sinai. Earlier this month the group pledged allegiance to the Islamic State, a militant group which has taken over areas of Iraq and Syria.