Mina Aboud Sharween, a Coptic Christian priest, was killed in Egypt Saturday in what some Egyptians are labeling as the first sectarian killing since Mohamed Morsi’s ouster Tuesday.

Sharween was shot and killed in Sinai near the Gaza strip while walking in the Masaeed section of El Arish, the Guardian reported. He was found dead by his daughter on Wednesday, according to CBN.

It’s unclear whether the Muslim Brotherhood, the militant Islamist group that backed Morsi’s presidency, was behind the attack or if the group’s followers were responsible for shooting and killing the Coptic Christian priest. But it was believed that the attack was the work of the Islamic insurgents, Reuters reported.

The Muslim Brotherhood had harsh words for Coptic Christian leader Pope Tawadros, the spiritual head of Egypt’s 8 million Coptic Christians. Tawadros gave his blessing to remove Morsi from power and was with military leaders, including Gen. Abdel Fatah al-Sisi, when al-Sisi declared Egypt was suspending its constitution.

“Millions will remain in the squares until we carry our elected president, Mohamed Morsi, on our shoulders,” Muslim Brotherhood leader Mohammed Badie said in Cairo on Friday, according to the Telegraph. “We are his soldiers and we defend him with our lives.”

The Muslim Brotherhood leader singled out Tawadros and the Grand Imam of Al-Azhar University as those who supported Morsi’s ouster. The remarks may be seen as a threat to the two leaders and may cause more sectarian violence in Egypt, the Telegraph noted.

Egypt is operating under an interim government since Morsi was ousted from power in a military coup Tuesday. Adly Mansour, Morsi’s  successor, has so far not indicated when elections will be held.