Islamic State has claimed responsibility for a suicide bombing at Cairo's main Coptic cathedral that killed 25 people, mainly women and children.
The militant group said in a statement that a suicide bomber whom it identified as Abu Abdallah al-Masri had detonated his explosive belt inside the church.
It also threatened more attacks against Christians.
"Every infidel and apostate in Egypt and everywhere should know that our war ... continues," the group said in the statement, published by its Amaq news agency.
At least 25 people have been killed and 49 wounded in a bombing at in Egypt's main Coptic Christian cathedral in Cairo.
The blast took place as a Sunday mass being held in the chapel was about to end.
Most of the victims are thought to be women and children.
A bomb was thrown into a chapel close to the outer wall of St Mark's Cathedral, Egypt's MENA news agency reported.
However witnesses have also said the explosion may have been caused by a planted device.
An angry crowd of several hundred people gathered outside the cathedral, chanting anti-government slogans and calling for the sacking of the interior minister, who is in charge of security.
Scuffles broke out with the police when the protesters tried to push through their barricades, but there were no immediate reports of arrests.
Police in full riot gear later arrived at the scene.
It is the second deadly attack to hit the Egyptian capital within two days.
On Friday, six policemen were killed in a bomb attack claimed by a militant group. There was no immediate claim of responsibility for Sunday's attack.
Eight policemen were killed in an armed attack on a police car in Egypt on Sunday.Read the full story ›
Five bombs exploded in Cairo today killing one person and wounding five others.
Three police officers were injured when one of the bombs went of near a police station in the district of Alwaraq, the Egyptian Interior Ministry said in a statement.
One person was killed and a further two wounded when one of the devices went off outside a restaurant in a residential district of the Egyptian capital.
The other three bombs resulted in damage to businesses, including a Vodafone shop, but there were no reports of injuries in the middle-class district of Mohandeseen, where most of the attacks took place.
Egypt has experienced an influx in violence since General Abdel Fattah al-Sisi (now President Sisi) overthrew Mohamed Morsi in 2013. Most of the ensuing violence has taken place in the restless Sinai Peninsula.
The British embassy in Cairo is closed for what appears to be security reasons.
Officials said they would not disclose any details due to "the sensitive nature of the matter", but reports emerged of plans by militants to "target foreign embassies".
Meanwhile, the US embassy in Cairo, which is located on the same street as the British embassy, remains open.
Reports have surfaced that the closure of the British embassy in Cairo today could have been because of plans by militants to "target foreign embassies".
The embassy has declined to give details of the security concerns that led to it closing its doors today due to "the sensitive nature of the matter " but speculation has been mounting as to why it was shut.
An anonymous source told Reuters that a suspected militant who was recently detained by Egyptian authorities had confessed to planning to target foreign embassies.
The British Embassy in Cairo has said they are working with Egyptian authorities to reopen its doors after suspending public services for security reasons.
No further details as to why the embassy has been shut have been released because of the "sensitive nature of the matter".
A message on the foreign office website reads: "Please do not come to the embassy building."
The British Embassy in Cairo has suspended its public services for security reasons today.
The office of the British Consulate-General in Alexandria will continue operating as normal.
Hundreds of journalists are to protest In London later today over the jailing in Egypt of colleagues from Al Jazeera which has provoked outrage around the world.
Staff from the BBC and other news organisations will hold a one minute silent protest outside New Broadcasting House in London at 9.41am-the time of yesterday's sentencing.
Australian-born Peter Greste, Canadian-Egyptian Mohammed Fahmy, and Egyptian producer Baher Mohammed were each sentenced to seven years in prison over alleged terrorism charges.
The imprisonment of the journalists on charges relating to terrorism provoked Foreign Secretary William Hague to summon the Egyptian ambassador in London for a meeting yesterday.
A bomb in Cairo has wounded at least three people near an election event in support of Egyptian presidential candidate Sisi al-Ahram, state-run newspaper Al-Ahram said.
A man reportedly threw a home-made device in the direction of Sisi's supporters. Sisi was not present at the rally.