Between 25 and 30 men suspected of being affiliated with the Islamic State (ISIS/ISIL) carried out the deadly assault on a Sufi mosque in Egypt’s Sinai while donning military combat uniforms.

They arrived at the scene of the crime at the al Rawdah Sufi mosque on Friday armed with automatic machine guns and driving in five SUVs, reports CNN.

Citing comments made by the state prosecutor to the state-run Nile TV, the news network adds, “Some wore masks, and at least one was carrying an ISIS flag. … They positioned themselves at the building’s entrances and the front of the mosque shortly before the massive gunfire, and loud explosions rang out.”

The jihadists killed an estimated 305 people, including 27 children, and wounded an additional 128, the prosecutor reportedly revealed over the weekend.

Some news outlets have deemed the incident the deadliest terrorist attack in Egypt’s history.

“The al Rawdah Sufi mosque is known as the birthplace of an important Sufi cleric. Sufism is a mystical branch of Islam that some jihadists consider heretical,” acknowledges CNN.

ISIS terrorists have reportedly attempted to justify the heinous attack, claiming the Sufi target cannot be considered a mosque.

“It’s a mistake to claim that the site that was attacked was a mosque,” Abou Abdelrahman al-Maqdesi, an ISIS-aligned jihadist in Gaza, told Breitbart Jerusalem. “It was a house of worship where infidel activities were performed against sharia. Those who were harmed were not civilians. They are people who call themselves ‘Sufis.’ That’s another name for one of the infidel groups. They committed acts against Islam and our supreme sharia.”

Al-Maqdesi alleged that Islamic religious law prevents “the site that was attacked” from being “considered a mosque.”

Anonymous witnesses told CNN that very few worshippers, at best, were able to escape the attack inside the mosque.

One unnamed survivor indicated to the news network that “he still had shrapnel in an eye, adding that ‘he believes he survived because he was covered by the bodies of other victims as the attackers went around the mosque to ensure everyone was dead.’”

“No one got out of the mosque,” another witness told CNN.

In response to the attack, Egyptian President Abdel Fattah el-Sisi has vowed to respond with “brute force.”

On Saturday, Egyptian warplanes reportedly targeted “terrorist outposts” containing weapons, ammunition and radical elements following with airstrikes.