CAIRO, Feb 16 (Aswat Masriya) – The airstrikes carried out by Egypt's airforce against militant targets in Libya involved the use of six F-16s, Egypt's newest fighter aircrafts, an Egyptian military source told Aswat Masriya. 

Egypt's air force carried out airstrikes coordinated with the Libyan air force against Islamic State Fighters in Libya on Monday dawn, after a video surfaced showing the beheadings of 21 Egyptian nationals in Libya. 

Another Egyptian military said the strikes were carried out in the Libyan cities of Derna and Sirte. 

The Egyptian armed forces said in a statement that the strike was "precise," adding that the air force troops have safely returned to their bases.

Egypt's army said the target of the strikes is "training points and weapons and ammunition storage" sites belonging to the Islamic State Fighters in Iraq and Syria, on Libyan soil.

Libyan Air Force Chief of Staff Sakr al-Joroushi was cited by Reuters as telling al-Arabiya satelite channel that the strikes were coordinated and that more strikes would be carried out tomorrow.

Reuters has also cited Joroushi as telling Egyptian state television that strikes have left no less than 40 or 50 militants dead. 

Late on Sunday a video titled "a message signed with blood to the nation of the cross." It showed masked men beheading 21 Egyptian Copts who had been kidnapped in Libya for weeks.  

The men responsible for the beheading are believed to belong to a division of Islamic State Fighters in Libya.   

In response, President Abdel Fattah al-Sisi said in a televised address that "Egypt reserves the right to respond in the method and timing it deems suitable for retribution from these killers."

The decision to strike Libyan targets comes after an urgent meeting of Egypt's National Defence Council, which Sisi called for.  

Fighting in Libya has intensified since the overthrow of late Libyan President Muammar Gaddafi in 2011, reaching unprecedented levels over the past year.

Several Egyptians have been caught up in the militant fighting gripping the neighbouring country.

Egypt's ministry of foreign affairs to has for months issued warnings to all Egyptians residing in Libya, calling on them to avoid conflict areas and "seek safer areas" in Libya or "return home".  

In his televised address after the video's release, Sisi said a ban issued last month on Egyptians' travel to Libya will be fully enforced. 

The president is currently paying respects at a ceremony in St. Mark’s Cathedral. 

A spokesman of Egypt's Coptic Orthodox Church had described the video as "painful" on Sunday, confirming the identities of the deceased.