Egypt’s airstrike on Islamic State (IS) militant hideouts in Libya on Monday is “quick retribution” for the beheading of 21 Coptic Christian Egyptians, but is “not enough,” head of the Military Studies Centre Alaa Ezz El-Din has told Ahram Online.

Ezz El-Din believes that "more airstrikes should be launched against them,” so that the militant group “feel that any harm to Egyptian citizens will cost them greatly."

Furthermore, Egypt should initiate the creation of an Arab military coalition to fight the militants and impose stability in Libya through supporting the Libyan army and the legitimate Libyan government, says Ezz El-Din.

Ezz El-Din says that the Arab League should lead this coalition.

“No foreigners or non-Arabs should interfere in Libyan territories,” he says.

This coalition force would be a legitimate entity, according to Ezz El-Din, since the United Nations gives regional institutions the right to resolve conflicts that threaten the peace and stability of surrounding countries.

A video surfaced late Sunday on YouTube allegedly showing IS militants beheading 21 Coptic Christian Egyptians on a beach in Libya’s Tripoli. "Egypt reserves its right to retaliate at the suitable time and place,” Egyptian president Abdel-Fatah El-Sisi said in a speech shortly afterwards.

Egypt’s fighter planes hit IS targets in Libya’s Derna and Sirte, killing 64 IS militants, in coordination with the Libyan army, Libyan army spokesperson Major Mohamed Hegazy said on Monday. Egypt is yet to release any details about the airstrikes.

Ezz El-Din says that Egypt’s current air strikes in Libya won't increase Islamist militant attacks in Egypt, as “criminals in Egypt are decreasing rapidly because of successful security strikes [against them].”

Egypt has suffered from numerous Islamist militant attacks lately, especially in North Sinai, where a decade-long militancy has spiked in the last year and half.

Militant group Ansar Beit El-Maqdis, who have claimed most of the attacks in the troubled Sinai peninsula, in late 2014 declared their allegiance to IS.

Hundreds of police and army personnel have reportedly been killed and injured in the group's attacks, while hundreds of militants have reportedly been killed in the army’s campaign against them.