Coptic Orthodox Church spokesman Bouls Halim said the death toll in Friday's attack was likely to rise. Local church officials in Minya province where the attack took place, put the death toll at 10, but the higher figure could not be confirmed.

No group immediately claimed responsibility for the attack, which bore the hallmarks of Islamic State militants who have for years been fighting security forces in the Sinai Peninsula and along Egypt's porous desert border with Libya.

Friday's attack is the second to target pilgrims heading to the St. Samuel the Confessor monastery in as many years. The previous attack in May 2017 left nearly 30 people dead.

The Interior Ministry, which oversees the police, said the attackers used secondary dirt roads to reach the bus carrying the pilgrims, who were near the monastery at the time of the attack.

The attack last year was the latest in a deadly series that targeted churches in Cairo, the Mediterranean city of Alexandria and Tanta in the Nile Delta north of the capital. Those attacks, all claimed by the Islamic State group, left at least a 100 people dead and led to tighter security around Christian places of worship and other Church-linked facilities.

Egypt's Christians, who account for some 10 percent of the country's 100 million people, complain of discrimination in the Muslim majority country. The Coptic Church allied itself with President Abdel-Fattah el-Sissi when he, as defense minister, led the 2013 military overthrow of an Islamist president, Mohammed Morsi.