At least ten people were killed in a shootout outside a church south of Cairo on Friday, state-media reported.
"The security forces frustrated an attack on church in Mar Mina Church in the Helwan district," said a statement from Interior Ministry.
One attacker was killed and another has fled the scene on a motorbike, the statement said. It added two policemen were killed in exchange of fire.
Egyptian Health Ministry said the death toll rose to ten, including two Muslims, the attacker and the policeman, and eight copts, adding at least five others were wounded.
Two of the wounded are in serious conditions, the health ministry added.
Bombs-disposal team has defused two bombs planted nearby the church.
The security forces have been chasing the militants in the desert areas surrounding the church, official news agency MENA reported.
No group has yet claimed responsibility for the attack.
The Islamic State group's affiliate in Egypt has killed dozens of Christians in church bombings and shootings over the past year.
Egypt's Coptic Christians, the largest religious minority in the region, make up about 10 percent of the country's 93 million people.