Updated

The Islamic State terrorist group claimed responsibility for the attack on a bus outside of Cairo that killed at least 29 Coptic Christians including 10 children.

The group's news agency, Aamaq, said Saturday morning, its soldiers carried out the attack early Friday as a group of Coptic Christians who were reportedly on their way to a monastery south of Cairo. Group said put the death toll at 32.

The discrepancy in casualty figures is not uncommon in the aftermath of major attacks by the militants, who have been waging an insurgency centered at northern Sinai, though attacks on the mainland have recently increased.

The Egyptian Cabinet said in a news release that 13 victims of Friday’s attack remained hospitalized in Cairo and the southern province of Minya where the attack to place.

The attack was the fourth to target Egypt’s Christian community since December. The bloodshed came on the eve of the start of the Muslim holy month of Ramadan.

As many as 10 masked attackers in three SUVs stormed the bus dressed in military uniforms and demanded that the passengers recite the Muslim profession of faith, witnesses said, according the Wall Street Journal. Then, the gunmen opened fire.

Three children on board the bus reportedly survived.

Hours after Friday's attack, President Abdel-Fattah el-Sissi announced that Egypt had launched airstrikes against militant training bases in Libya.

Senior Egyptian officials said fighter jets targeted bases in eastern Libya of the Shura Council, an Islamist militia known to be linked to al-Qaida, not the Islamic State grop. There was no immediate word on damage or casualties.

El-Sissi told Pope Towadros II, the pope of the Coptic church in Egypt, in a phone call on Friday that the state would not rest easy until the perpetrators of the attack were punished.

El-Sissi declared a three-month state of emergency following the targeting of two churches north of Cairo on Palm Sunday. In December, a suicide bomber targeted a Cairo church. The three attacks, for which the Islamic State group claimed responsibility, left at least 75 people dead.

On Friday, President Donald Trump vowed to crush “evil organizations of terror.”

In a sharply worded statement, Trump condemned terrorists who were "engaged in a war against civilization" and decried the "merciless slaughter of Christians in Egypt."

El-Sissi, in his televised address, said of the U.S. president: "I direct my appeal to President Trump: I trust you, your word and your ability to make fighting global terror your primary task."

He said the attack on a bus carrying Christians, many of them children, would steal the nation's resolve to destroy terrorist organizations and expose "their depraved, twisted and thuggish ideology."

The Associated Press contributed to this report.