Gunmen shot dead a Coptic Christian priest in Egypt's lawless Northern Sinai on Saturday in what could be the first sectarian attack since the military overthrow of Islamist President Mohamed Morsy, security sources said.

The shooting in the coastal city of Arish was one of several attacks believed to be by Islamist insurgents that included firing at four military checkpoints in the region, the sources said.

Morsy's Muslim Brotherhood has fiercely criticized Coptic Pope Tawadros, spiritual leader of Egypt's 8 million Christians, for giving his blessing to the removal of the president and attending the announcement by armed forces commander General Abdel Fattah al-Sisi suspending the constitution.