Gunmen opened fire on a Coptic church in a Cairo suburb on Friday, killing at least nine people.
ISIL claimed responsibility for the attack on the church of Mar Mina in the district of Helwan, without providing evidence for the claim.
In a statement released via its propaganda agency Amaq, it said a group of its "soldiers" had carried out the attack, killing "crusaders" and police officers.
It added that one of its fighters had been killed.
Sheikh Mohammed bin Zayed Al Nahyan, Crown Prince of Abu Dhabi and Deputy Supreme Commander of the UAE Armed Forces, made a phone call to Egyptian President Abdel Fattah El Sisi on Friday night, offering condolences for the victims of the attack.
Sheikh Mohammed reaffirmed the UAE's solidarity with Egypt and support in standing up against the scourge of terrorism, state news agency Wam reported.
President Sisi thanked Sheikh Mohammed and expressed Egypt's appreciation for the support given by the leadership and people of the UAE.
He also stressed the need to enhance joint Arab action to overcome various challenges facing the nation, including terrorism.
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The two attackers opened fire at the entrance to the church of Mar Mina in Helwan district, which was being guarded by police in the run-up to Orthodox Christmas celebrations next week, security sources said.
One attacker was shot dead by security forces, the sources and the state-run news agency Mena reported. State television said the second had been captured.
The health ministry said that nine people had been killed on Friday in addition to the gunman, and five wounded, including two women in serious condition.
Local media said the dead attacker had been wearing an explosive belt, and that two other bombs had been defused near the church.
Cellphone footage posted on social media appeared to show the bearded gunman wearing a bulky ammunition vest sprawled on a street, barely conscious, as people restrained his arms and then handcuffed him.
ISIL's local affiliate has claimed several attacks on Egypt's large Christian minority in recent years, including two bomb attacks on Palm Sunday in April and a blast at Cairo's largest Coptic cathedral last December that killed 28 people.
Police have stepped up security measures around churches ahead of the Coptic Christmas celebrations on January 7, deploying officers outside Christian places of worship and setting up metal detectors at some of the bigger churches.
Egypt's Coptic Christians make up about 10 per cent of the country's 93 million people, and are the largest religious minority in the region.
ISIL militants are believed to have also carried out a massacre of Muslim worshippers in Sinai last month, killing more than 300 in an attack on a mosque associated with the mystical Sufi strand of Islam which ISIL views as heretical.
Egypt imposed a state of emergency following the church attacks and shootings, and President Abdel Fattah El Sisi demanded the army quell the extremists with "brutal force" following the mosque massacre.
The group has been waging a deadly insurgency based in the Sinai peninsula bordering Israel and the Gaza Strip that has killed hundreds of policemen and soldiers.
They have increasingly targeted civilians as attacks on the security forces have become more difficult.
The army has poured in thousands of troops backed with armour and jets in a bid to crush the Sinai-based militants, but attacks have continued.
The attack on the church came a day after six Egyptian soldiers were killed in a roadside bombing in the Sinai.
Last week, ISIL claimed responsibility for firing an antitank missile at a helicopter in a North Sinai airport as the defence and interior ministers were visiting.
The attack killed an aide to the defence minister and a helicopter pilot, but both ministers returned to Cairo unscathed.