Local media reported three passerbys were killed.
The Coptic Church said the gunman first shot at a Christian-owned shop 4km away, killing two people, before proceeding to the Mar Mina church in the southern Cairo suburb of Helwan.
Gunmen killed at least nine people, including three police officers, in an attack on a Coptic Christian church south of Cairo yesterday, medical and security sources said.
During a Palm Sunday service in April more than 40 people were killed and many more injured by bomb attacks in two separate cities and in May almost 30 people were killed when gunmen attacked a bus carrying Coptic Christians to a monastery.
"The Secretary-General calls for those responsible for today's horrific attack to be swiftly brought to justice", the statement concluded.
JetBlue flight slides off Logan Airport taxiway
Firefighters loaded passengers into buses which took them back to the airport terminal after the spin. Taxiways are the "roads" that planes use to roll to and from runways. "Pilot did a fantastic job".
The Islamic State group's affiliate in Egypt has killed dozens of Christians in church bombings and shootings over the past year.
The attack came amid tightened security around churches and Christian facilities ahead of the Coptic Orthodox Christian celebrations of Christmas on January 7. The Interior Ministry said he opened fire at the entrance to the site and tried to throw an explosive device.
The ministry said security forces had "immediately dealt with the (attacker) and arrested him after he was wounded".
Earlier, security officials who spoke on condition of anonymity said two police were killed. It also said there was a separate attack on a store in the same neighborhood of Helwan that killed two Copts.
One attacker was shot dead by security forces, the sources and the state-run news agency Mena reported. The officials requested anonymity because they were not authorized to brief the media. Authorities have closed off the area around the church.
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