Masked gunmen dressed in military uniforms attacked a group of Coptic Christians south of the Egyptian capital on Friday, killing 26 people and wounding 26 others as they were driving to a monastery, medical sources and eyewitnesses said.

The group was traveling in two buses and a small truck in Minya province about 220 kilometers south of Cairo, the sources said. The province is home to a sizable Christian minority.

Provincial governor Essam al-Bedaiwy said earlier that 23 people had been killed and 25 wounded.

Eyewitnesses said the Copts were attacked as they were going to pray at the monastery of Saint Samuel the Confessor in the western part of the province.

They said masked men wearing military uniforms stopped the vehicles on a road leading to the monastery and opened fire.

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 ISIS. There was no immediate claim of responsibility for Friday’s attack, which came on the eve of the holy Muslim month of Ramadan.

Egypt has been fighting ISIS-linked militants who have waged an insurgency, mainly focused in the volatile north of the Sinai Peninsula but there have been also attacks on the mainland.

Following Friday’s attack, security forces launched a hunt for the attackers, setting up dozens of checkpoints and patrols on the desert road.

The grand imam of al-Azhar said the attack was intended to destabilise the country.

“I call on Egyptians to unite in the face of this brutal terrorism,” Ahmed al-Tayeb said from Germany, where he was on a visit.

President Abdel Fattah al-Sisi called a meeting of security officials, the state news agency said.