A member of the Egyptian security stands guard in front of the restaurant that was attacked in Cairo, Egypt, December 4, 2015. REUTERS/Mohamed Abd El Ghany

BEIRUT — An explosion at a Cairo nightclub killed 16 people and injured at least five others early Friday morning, in an attack that Egypt’s Interior Ministry labeled as “revenge” from patrons who were previously denied entry to the venue.

The explosion came from a Molotov cocktail thrown into the enclosed area in Agouza, in Egypt’s Giza district, in the vicinity of several prominent government buildings, including the Ministry of Foreign Affairs. Egyptian security forces are looking for two or three masked men who are suspected of carrying out the attack, Egypt’s state-run television news agency MENA reported.

Investigation by security services revealed there had been an altercation between employees and patrons. The men who were refused entry threw Molotov cocktails at the door of the club out of revenge, the Interior Ministry wrote in a statement posted to its official Facebook page.

The venue has been identified as El Sayyad (The Fisherman), a restaurant that doubles as an underground nightclub, located in the basement of an old building. Patrons had only one entry and exit route out of the building, and consequently victims were either burned to death or succumbed to suffocation from smoke inhalation. Among the dead are five women and 11 men.

Earlier on Friday, Egyptian security officials told Reuters that at least one of the attackers was suspected of being a former employee of the institution. The Interior Ministry statement did not confirm nor deny this.

There has been no connection made with militant groups operating inside of Egypt that have been carrying out numerous attacks across the country since former President Mohammed Morsi was ousted in 2013.

This is a developing story.