Dawn Attack On Libya By Egypt In Retaliation

The attack, in which Libya's air force also took part, focused on camps, training sites and weapons storage areas across the border between the two countries.

 A Libyan air force commander told Egyptian state television that 40-50 militants were killed.

Saqer al Joroushi said the strikes by war planes loyal to the official government had been coordinated with Egypt and more would follow.

He said Egyptian and Libyan planes had combined to hit targets in the eastern town of Derna. Libyan planes then attacked the central cities of Sirte and Ben Jawad, he added.

A spokesman for Egypt's Armed Forces General Command said the strikes were "to avenge the bloodshed and to seek retribution from the killers".

"Let those far and near know that Egyptians have a shield that protects them," the statement added.

The strikes come after video emerged showing 21 handcuffed hostages dressed in orange jumpsuits being murdered by militants identified as being from the Tripoli Province of Islamic State.

In the latest issue of the IS online magazine Dabiq, the group had said the same number of Egyptian hostages were being held in Libya after being kidnapped in January.

Security officials say the militants in Libya have established ties with Sinai Province, a group that operates from Egypt's Sinai Province and has pledged allegiance to IS.

Britain's Prime Minister David Cameron described the killings as "a cruel and barbaric act", adding: "We will not waver in our fight against terrorists and extremism."