This image made from a video released Feb. 15 by militants in Libya purportedly shows Egyptian Coptic Christians in orange jumpsuits being led by masked militants. The video later appears to show the militants killing the Egyptians. (AP)

In retaliation for the gruesome killing of Egyptian Christians on a beach in Libya, Egypt sent its air force on the attack against Islamic State targets there Monday, in a move that threatened to ensnare Egypt in a regional conflict with the militants.

Egypt’s Foreign Ministry on Monday called on the U.S.-led coalition striking Islamic State targets in Syria and Iraq to broaden its scope to North Africa and take action against the extremist group in Libya. Italy said it would weigh a military intervention in its former colony across the Mediterranean to thwart the Islamic State.

Libya’s air force also said that it had launched raids against militants in eastern Libya in coordination with Egypt and that the strikes had killed more than 60 fighters. The chief of staff for Libya’s air force told Egyptian state television that the raids would continue Tuesday.

Egyptian fighter jets targeted Islamic State training camps and weapons stocks in Libya in a wave of dawn airstrikes, according to a statement from the Egyptian armed forces. Egypt’s military did not specify where its strikes took place.

“We must take revenge for the Egyptian blood that was shed,” said the statement from Egypt’s military, which was posted along with a video of a warplane taking off at night. Later, the army posted footage of four strikes it said were carried out on “Libyan soil.”

“Seeking retribution from murderers and criminals is our duty,” the army said. “Let those far and near know that Egyptians have a shield that protects them.”

The statement marked the first time Egypt has publicly acknowledged military involvement in Libya, which has been torn apart by political chaos since an uprising that ousted longtime dictator Moammar Gaddafi in 2011. In August, U.S. intelligence officials said Egypt was carrying out strikes against Islamist groups in Libya in joint operations with the United Arab Emirates. Egypt denied those claims, however.

Islamic State militants released a horrific video Sunday of the beheading of 21 Egyptian Christians who had been taken hostage in the Libyan city of Sirte in two separate incidents in December and January.

In the video, masked jihadists marched the Christians, who were from Egypt’s Coptic minority, onto a sandy beach and forced them to their knees before sawing off their heads.

The brutal killings were portrayed as retaliation against what the video referred to as “the hostile Egyptian church.” Captions refer to Kamilia Shehata, an Egyptian Coptic woman who in 2010 was rumored to have converted to Islam before police and the church clergy isolated her. The Coptic Church in Egypt said Sunday that it had identified the men in the video as the missing Egyptians.

The footage was the first propaganda video from the Libyan branch of the Islamic State, which in Iraq and Syria has declared a caliphate over a wide swath of territory under its rule.

At the Vatican, Pope Francis paid tribute to the victims.

“The blood of our Christian brothers is a testimony which cries out to be heard. It makes no difference whether they be Catholics, Orthodox, Copts or Protestants. They are Christians. Their blood is one and the same,” he said.

In Beirut, the leader of the Hezbollah movement, which has been fighting the Islamic State in Syria and now Iraq, condemned the beheadings.

At least three militant groups in Libya have pledged allegiance to the Islamic State, announcing “provinces” of the caliphate in the south, east and around the capital, Tripoli, in the west. Libya’s turmoil has allowed the extremists to make inroads into several cities.

A political crisis has split Libya’s leadership and the armed groups that proliferated after the uprising into two vying governments — one in Tripoli led by Islamists and another in Tobruk that is recognized by the international community.

In the fracturing of the country since the removal of Gaddafi, Egypt has backed more-secular forces aligned with former Libyan general Khalifa Hifter, who launched his own offensive against Islamist militants in the eastern city of Benghazi last spring. Egypt shares a porous 700-mile border with Libya.

In Rome, officials said Italy would weigh participating in a military intervention to keep forces from the Islamic State group from advancing in Libya should diplomatic efforts fail, the Associated Press reported.

Defense Minister Roberta Pinotti has said Rome could contribute 5,000 troops to lead such a military mission. But Prime Minister Matteo Renzi said Italy would defer for now to the U.N. Security Council.

Reports in Libyan media said Monday that air raids in the eastern city of Derna, a jihadist stronghold, had killed a number of people, but those reports could not be immediately verified.

Videos posted on social media purported to show destroyed buildings in Derna allegedly targeted in the strikes.

The Tripoli-based branch that claimed the beheadings also claimed responsibility for a deadly attack that killed 10 people, including one American, in a luxury hotel in the capital last month.

“The Egyptian people are shocked,” said Safwat al-Zayyat, a retired general in Egypt’s military. “But there is an attempt [by the jihadists] to drag Egypt” into war in Libya, he said.

“We must be cautious, as the Americans say, of putting boots on the ground.”

Liz Sly in Beirut contributed to this report.