Eyewitnesses said masked men travelling in three four-wheel-drive vehicles stopped the bus on the road and opened fire. Local television showed footage of a bus raked with gunfire and streaked with blood.

The attack was made on a desert road leading to the monastery of Saint Samuel the Confessor in Minya province, which is home to a sizeable Christian minority.

The latest massacre follows the shocking Palm Sunday attacks on April 9, when terrorists bombed the Tanta Church, in the Nile Delta region, and St Mark’s cathedral in Alexandria, killing more than 40 people.

Eight unidentified gunmen were reportedly responsible for yesterday’s attack. Security forces set up dozens of checkpoints and patrols on the desert road in a hunt for the attackers.

Meanwhile, President Abdel Fattah Al-Sisi, who called a three-month state of emergency after the April bombings, called a meeting of security officials and vowed that the attackers would not succeed in dividing the country.

Since last December, attacks by Islamic State on churches in Cairo, Alexandria and Tanta have led to about 70 deaths. In February and March hundreds of Christians in North Sinai fled from an IS campaign of murder, leading to fears that the Egypt’s Christians, who make up 10 per cent of the population, could become decimated, as in Iraq and Syria.

The new attack comes on the eve of Ramadan, the Muslim holy month, which extremist groups have indicated is an ideal time for terrorist attacks.