Egypt violence: Six police officers killed by militants in Cairo
Six policemen have been killed and three others injured in the Egyptian capital Cairo when a bomb exploded on a main road leading to the Giza pyramids.
The explosion, at a police checkpoint, was the deadliest attack on security forces in Cairo in over six months.
The area has been cordoned off, while a bomb disposal squad searches for any other possible explosives.
A recently emerged militant group called Hasm - or decisiveness - said it carried out the attack.
The group, described by Egyptian security forces as an armed wing of the Muslim Brotherhood, said it was behind an assassination attempt on a senior prosecutor in September.
Hasm accuses Egyptian judges of sentencing thousands of innocent people to death, or jailing them for life.
Hundreds of of Muslim Brotherhood supporters have received death sentences since 2013, when then-President Mohammed Morsi was overthrown by the army and arrested.
Mr Morsi came to power in the first free elections since the 2011 uprising which ousted Hosni Mubarak.
Insurgents have carried out a number of attacks in Egypt since then, most of them in the northern Sinai Peninsula, where Islamic State-linked militants are battling the army.