A retired US intelligence official has said there is a real Islamist presence in Libya, and that it could be affiliated with the Islamic State of Iraq and Syria.

"There's been a real radical Islamist presence in Libya for some time," Lt. Col. Rick Francona, Ret., told CNN. "What's worrying is now they are self-identifying with ISIS."

These statements come in the wake of the ISIS murder of 21 Egyptian Coptic Christians they kidnapped in Sirte, Libya in December and January. After the Islamic State published a video of the Christians' execution, Egypt launched airstrikes on early morning Monday against suspected ISIS training camps and supply depots within Libya. 

Francona said that the Western countries and its allies may find it difficult to keep the Islamic State in check if it expands to northern Africa. 

"While we can come up with a military solution or a military operation in a restricted area like Syria and Iraq, what do we do when it expands to North Africa?" the retired intelligence official said, adding that the expansion into North Africa will present a "challenge" to leadership in Western countries.

CNN's analyst Peter Berger also agreed with Francona's assessment. "There's certainly communication between the Libyan affiliate and the affiliate in Syria about matters of importance to both of them," he said, adding that this is because of the relationship between the Libyan jihadists and Al Qaeda, ISIS' predecessor. Berger described the relationship as going "back a very long time."

CNN reported this week that jihadists affiliated with the ISIS have occupied several cities in Libya, including Benghazi, Sirte and even Tripoli. It was also reported in November that jihadists were holding the city of Derna, a city that has a history with radical Islamist groups, near the Egyptian border.