The attack took place nearly at the exact location where 28 Christians were killed by Islamist militants in 2017.
In December 2017 an IS killed nine people in an attack on a church in a south Cairo suburb.
The attack took place on the road back from the Saint Samuel monastery, he added, as the bus was heading to the city of Sohag.
Egypt is carrying out a significant security and military offensive, mainly in Sinai, also on the border with Libya, to defeat militants behind a series of attacks on security forces and civilians, including Christians.
At least seven people were killed and more than 20 others were injured in an attack on a bus carrying Coptic Christians to a monastery in Egypt on Friday, according to a spokesperson for Egypt's Coptic Church.
Egyptian authorities have also convicted jihadists for their role in attacks against Copts.
No group immediately claimed responsibility for the attack near St. Samuel the Confessor monastery in Minya, but extremists linked to ISIS have regularly targeted Christians.
Security forces are now searching for the unknown gunmen who carried out the terror attack on the bus, the sources said.
Egypt is a Muslim-majority country and its Christian minority - mostly members of the Coptic Orthodox Church - make up around 10% of the population. Christian activists say the church's alliance with el-Sissi has offered the ancient community a measure of protection but failed to end frequent acts of discrimination that boil over into violence against Christians, especially in rural Egypt.
"Terrorists attacked their bus on the way to (St) Samwil Monastery in Minya".