State media said a group of around 50 Coptic Christians travelling towards the monastery of Anba Samuel near Minya, about 150 miles from Cairo, was targeted by “armed terrorists”.
At least 23 people are reported to have been killed and a further 25 wounded.
Minya’s provincial governor, Essam al-Bedaiwy, said the group had been travelling in two buses and truck when the attack happened, Reuters reported.
Minya is home to a sizable Christian minority.
Christians make up around 10 per cent of Egypt’s 92 million population and have repeatedly been targeted by Islamic extremists.
It is the latest fatal attack on Copts in Egypt in the past few months, after more than 45 people were killed in a double suicide bombing in April, when terrorists attacked churches in Tanta and Alexandria on Palm Sunday.
ISIS claimed responsibility for both bombings.
No group has yet claimed responsibility for the latest atrocity.
More to follow.