Earlier reports by security sources and state media said at least two attackers were involved, and that one was shot dead and another fled the scene.
A gunman fired at worshippers and Egyptian police stationed outside a Coptic Orthodox church near Cairo and killed nine people before being wounded and arrested.
The church attack is part of a "ongoing crisis" in Egypt, said Omar Ashour, a professor of security studies at the Doha Institute.
A gunman on a motorcycle opened fire outside the church and at a nearby store, sparking a shootout that killed at least nine people, including eight Coptic Christians, in the latest attack targeting the country's embattled Christian minority.
Security officials said the exchange of fire also injured five other people, including two women who are in a serious condition.
USA embassy announces end to visa crisis with Turkey
Meanwhile, the Turkish Embassy in Washington D.C. has also lifted visa restrictions for the USA citizens. Both countries restarted visa issuances in November, but only on a limited basis.
A video circulated on social media after the attack appeared to show the dead gunman on the ground.
Egypt's Christian minority has been targeted by Islamic militants in a series of attacks since December 2016 that left more than 100 dead and scores wounded. Isis also claimed responsibility last week for firing an anti-tank missile at a helicopter at an airport in northern Sinai as the defence and interior ministers were visiting.
The claim, which was carried by the group's Aamaq news agency, said Friday's attack was carried out by a "security detail" and that one of its men was "martyred" in it.
Pope Tawadros II says that since 2013 there have been 37 sectarian attacks on Christians in Egypt, almost one incident per month.
Furthermore, President Sisi received a phone call from U.S. President Donald Trump, who offered condolences over the victims of a terrorist attack in Cairo.