A gunman killed at least 11 people in attacks on a Coptic Orthodox church and a Christian-owned shop near Cairo before he was wounded and arrested, the Egyptian interior ministry and church officials said.
Islamic State claimed responsibility for the attacks, in a statement by its Amaq news agency, though it provided no evidence for the claim.
Police have stepped up security measures around churches ahead of Coptic Christmas celebrations on January 7, deploying officers outside Christian places of worship and setting up metal detectors at some of the bigger churches.
Islamist militants have claimed several attacks on Egypt's large Christian minority in recent years, including two bombings on Palm Sunday in April and a blast at Cairo's largest Coptic cathedral in December 2016 that killed 28 people.
Earlier reports by security sources and state media said at least two attackers were involved in the attack, and that one was shot dead and another fled the scene. The interior ministry did not explain the reason for the different accounts.
US President Donald Trump spoke by phone with Egyptian President Abdel Fattah al-Sisi and condemned the attack, the White House said in a statement.
The Coptic Church said the gunman first shot at a Christian-owned shop 4 km away, killing two people, before proceeding to the Mar Mina church in the southern Cairo suburb of Helwan. The Interior Ministry said he opened fire at the entrance to the site and tried to throw an explosive device.
The gunman killed at least nine people, including a policeman, at the church, according to Interior Ministry and Coptic Church accounts. The Church said a young woman had died later from her wounds, bringing the civilian death toll at the church to eight.
The ministry said security forces had "immediately dealt with the (attacker) and arrested him after he was wounded." It added, "Legal measures have been taken," without elaborating.
Investigators have identified the gunman, it said, adding that he had carried out several attacks since last year. Egypt is also grappling with a deadly Islamic State insurgency in the North Sinai region.
The health ministry said five people had been wounded, including two women who it said were in a serious condition.
A joint funeral for eight of those killed was held on Friday evening at the Virgin Mary church in Helwan.
The head of the Coptic Church, Pope Tawadros II, led mourning for the victims. Egyptian President Abdel Fattah al-Sisi also offered his condolences to the families and ordered security forces to increase safety measures at sensitive sites, his office said in a statement.
"The shooting began at 10:30 am and carried on for more than 15 minutes ... There was more than one attacker," Mohammed Hussein Abdelhadi, who lives close to the church, told Reuters.
A witness who did not want to give his name said the policeman was killed while he was closing the church gate to stop the gunman getting in.
