An Egyptian police officer was killed on Saturday while attempting to defuse a bomb found near a church in an eastern Cairo suburb, state television reported, less than two days before Egypt's Christians celebrate the Coptic Christmas.
The device was one of two found inside a bag on a nearby rooftop, three security sources and state media reported.
Two policemen and an onlooker were also injured when the device exploded, the security sources said.
There was no immediate claim of responsibility. Egyptian security forces have for years battled Islamist insurgents who have attacked Coptic Christians, tourists and security personnel.
Security forces have stepped up their presence outside churches and other places of worship ahead of New Year's Eve and Coptic Christmas, which is celebrated on Jan. 7.
The Copts, who make up around 10% of the population, have long complained of discrimination. Authorities have placed armed guards outside churches and monasteries in an attempt to protect them from jihadist attacks.
In November, militants killed seven people returning from baptizing a child at a Coptic monastery about 260 kilometers (160 miles) up the Nile River from Cairo.
