Gunmen killed 23 Coptic Christians and wounded 25 others on Friday as they were driving to a monastery in Minya province, south of Cairo, the provincial governor, Essam al-Bedaiwy, said.
The group was traveling in two buses and a truck through the province, which is home to a sizeable Christian minority, he said.
Coptic Christians, who make up about 10 percent of Egypt's population of 92 million, have been the subject of a series of deadly attacks in recent months.
About 70 have been killed in bomb attacks on churches in the cities of Cairo, Alexandria and Tanta since December.
Those attacks were claimed by Islamic State. There was no immediate claim of responsibility for Friday's attack.