Voice of America reports a bomb blast has wounded at least four people on a public bus in Cairo.
A homemade device had been put on a traffic island and a second one, found nearby, was being dismantled. VOA says state television showed footage of a bus with its windows blown out.
On Tuesday, some 15 people died in the Nile Delta city of Mansoura after a police headquarters was bombed. VOA notes a hardline Islamist group based in the Sinai has claimed responsibility for that attack.
The group, Ansar Beit al-Maqdis, said the suicide car bombing was a response to the government's crackdown against Islamists, adds VOA.