Egypt-based Islamist militant Ajnad Misr group has claimed responsibility for Saturday's blast near Cairo University.
An improvised explosive device detonated outside a metro station near the university located in Giza, injuring eight people including policemen, according to Egypt's Health Ministry.
Later on Saturday, Ajnad Misr (Soldiers of Egypt) announced responsibility for the attack in a statement on its social media accounts. It also claimed that it had killed four policemen in the blast.
The group said the attack, that essentially targeted what the group described as "criminal [security] forces", also hit the personnel of private security companies, who were "previously warned".
Several Egyptian universities nationwide have hired private security companies in an effort to deal with on-campus Islamist protests that often ended in clashes with the police.
In the same statement, Ajnad Misr announced its responsibility for an attack on police forces outside the Ain Shams police station in northeast Cairo on 13 February that killed one policeman and injured eight others. They said that it was the third time that they had attempted to target police in the area.
These attacks, the group said, are part of Ajnad Misr's campaign called "Retribution is Life", in which it targets police for "killing… and harming" youth and detainees.
Ajnad Misr have claimed previous attacks in Cairo, including a blast that injured 11 at Cairo University last October. It also took responsibility for an explosion near the Ittihadiya presidential palace in June that killed two police officers, and a blast outside the foreign ministry in September that left two policemen dead.
Egypt has been facing a decade-long Islamist insurgency in the Sinai Peninsula, which has expanded outside the peninsula over the past two years.
Anti-government Islamist militants have repeatedly attacked police and army targets in Sinai, as well as in Cairo and the Delta, leaving hundreds dead and injured.
Civilians have also fallen victim during various violent attacks.