Militants detonated a bomb inside a crowded mosque in the Sinai Peninsula on Friday and then sprayed gunfire on panicked worshipers as they fled, killing at least 235 people and wounding at least 109 others. Officials called it the deadliest terrorist attack in Egyptinfo-icon's modern historyinfo-icon.

Police officers said militants attacked al-Rawdah mosque in the town of Bir al-Abd, 40 kilometers (25 miles) from the North Sinai provincial capital of el-Arish, during Friday prayers.

The attack reportedly targeted the supporters of Egyptian security forces attending prayers there.

No group has so far claimed responsibility for the attack, which had the hallmarks of the Daesh-affiliated Velayat Sinai terrorist group.

President Abdel Fattah el-Sisi convened an emergency security meeting soon after the attack, state television reported. The Egyptian president announced three days of national mourning.

The Sinai Peninsula has been under a state of emergency since October 2014, after a deadly terrorist attack left 33 Egyptian soldiers dead.

Over the past few years, militants have been carrying out anti-government activities and fatal attacks, taking advantage of the turmoil in Egypt that erupted after the country's first democratically-elected president, Mohamed Morsi, was ousted in a military coup in July 2013.

Velayat Sinai has claimed responsibility for most of the assaults. The group later expanded its attacks to target members of Egypt's Coptic Christian community as well as foreigners visiting the country. That has prompted the government to impose the state of emergency and widen a controversial crackdown, which critics say has mostly targeted dissidents.