At least 184 people were killed in Egypt and more than a hundred wounded after gunmen stormed a mosque in the Sinai Peninsula and set off a bomb.

Egyptian media said the explosion in the town of Bir al-Abed, roughly 100 kilometres from the border with Israel, occurred as worshippers gathered for weekly Friday prayers.

It struck the Rawda mosque, reported to be widely used by followers of the mystical Sufi branch of Islam.

The militants, reportedly in off-road vehicles, bombed the mosque and open fire during a sermon.

President Abdel Fattah el-Sisi convened an emergency meeting of security officials as three days of national mourning were declared, the state-run Middle East News Agency said.

The agency 120 people were wounded in the attack, citing official sources, but the number of casualties was expected to rise.

It is the deadliest attack to strike Sinai in the Egyptian authorities’ battle against Islamist extremists in the peninsula.

Hundreds of soldiers and militants have been killed in the four-year conflict.