The Islamic State terror group has claimed responsibility for an attack on a bus carrying Coptic Christians in Egypt in which 29 people were killed.
The group's news agency, Aamaq, said on Saturday that an IS unit targeted the bus as it travelled to a remote desert monastery south of Cairo on Friday, and 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 centred on northern Sinai, though attacks on the mainland have recently increased.
Egypt responded to the attack, the fourth by IS targeting the country's Christian minority since December with air strikes against what the military says are bases in eastern Libya where the militants have been trained.
The Egyptian Cabinet said in a news release on Saturday that 13 victims of the ambush remain in hospital in the capital and the southern city of Minya where the attack took place. Authorities had previously said 28 people were killed.
The attack came on the eve of the start of the Muslim holy month of Ramadan.
Hours afterwards, President Abdel-Fattah el-Sissi announced that Egypt had launched air strikes 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 IS. There was no immediate word on damage or casualties.
Mr 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.
The president 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 IS claimed responsibility, left at least 75 people dead.
Egypt's government has been struggling for the last three years to deter militants led by an Islamic State group affiliate and centred on the Sinai peninsula.
After a visit to Egypt last month by Pope Francis, IS vowed to escalate attacks against Christians and urged Muslims to steer clear of Christian gatherings and Western embassies.