The death toll in a terrorist attack on a mosque in Egypt's northern Sinai has risen to 305, with 27 children among the dead, Egypt's state prosecutor said on Saturday.
Another 128 people were injured as the Al Rawdah mosque, affiliated with Sufi groups, in the town of Bir al-Abed was bombed during Friday prayers by 25 to 30 armed men and fleeing worshippers were then gunned down.
Though no group has yet claimed responsibility for the attack, the state prosecutor said that the militants were carrying Islamic State flag, state news agency MENA reported. The case will be tackled as "an emergency supreme state security case," he added.
President Abdel Fattah el-Sisi vowed to respond to the massacre -- believed to be the deadliest terror attack on the country's soil -- with "brute force". He also ordered the armed forces to build a memorial for those killed at the mosque.
Egyptian warplanes conducted airstrikes on "terrorist outposts" and vehicles following the attack, the military said on Saturday. "The Egyptian Air Force pursued the terrorist elements, discovered and destroyed a number of vehicles that carried out the brutal terrorist killings and killed all terrorists inside those vehicles," military spokesman Tamer Rifai said.
It also targeted a number of terrorist outposts containing weapons, ammunition and radical elements, Rifai said.
"What is happening is an attempt to stop us from our efforts in the fight against terrorism," Sisi said in a televised address. "The armed forces and the police will avenge our martyrs and restore security and stability with the utmost force."
Dozens of gunmen surrounded the mosque in vehicles and opened fire on those trying to escape after bombs were set off. The militants were reported to have set seven parked vehicles on fire in the vicinity to block off access to the mosque and fired upon ambulances trying to help victims.
A witness told the Guardian he had heard calls for help emanating from other nearby mosques after the attack.
"I went with my family and friends to the scene of the mosque and found ambulances loading bodies and injured," he said. "What happened in al-Rawdah is a massacre against peaceful civilians."
"In the Ber al-Abd hospitals, there was chaos," he said. "Blood and screaming were everywhere."
Friday's attack prompted wide international condemnation, with Indian Prime Minister Narendra Modi and US President Donald Trump among the leaders expressing their condolences.
Landmarks and government buildings across the globe paid tribute to the victims. In Israel, which borders the Sinai peninsula, Tel Aviv's city hall was lit up with the Egyptian flag.
In Paris, the Eiffel Tower went dark to honour victims of the attack. In England's second largest city, The Library of Birmingham was lit up in the colors of Egypt's flag.
And in Canada's most populous city, Toronto, the CN Tower was also lit to honour of the victims.