A Coptic Christian priest has been killed in "a hail of bullets" outside The Church of the Martyr of St George in Sinai, Egypt today.

Raphael Moussa, 46, was shot dead by an unidentified gunman next to his car, having left the church in Arish where he attended a mass, according to Boulos Halim, a church spokesperson.

Security officials said there was more than one gunman involved in the shooting. They said the priest had been followed and shot at when he emerged from his car.

No one has claimed responsibility for the attack, but extremists in the Sinai have targeted Christians before, accusing them of working with the government.

A branch of ISIS has been active in the Northern Sinai region and reportedly killed hundreds of policemen and soldiers in the region.

"The whole situation in El-Arish and North Sinai is under threat," said Halim. "Many people [Christians] have left."

Christians, mostly Orthodox Copts, account for about 10 per cent of Egypt's population, which is overwhelmingly Sunni Muslim.

Sectarian violence sometimes erupts over disputes on issues related to church building, religious conversions and interfaith relationships.

The United States Commission on International Religious Freedom (USCIRF) last month recommended that the US State Department add Egypt to its list of "countries of particular concern", where "particularly severe violations of religious freedom are perpetuated or tolerated".

Though the Egyptian government has taken "positive steps to address some religious freedom concerns" in the past year, there remains a "climate of impunity", the USCIRF said.