Unknown gunmen have attacked a bus carrying Coptic Christians in southern Egypt, killing at least seven people, a church official says, Daily Sabah reported.

14 others were injured when gunmen started shooting at the bus after intercepting it en route to St Samuel monastery in the southern province of Minya, church spokesman Bishop Boulis Halim told dpa.

There was no immediate comment from police.

Egypt has seen a spate of militant attacks since 2013, when the army deposed president Mohammad Morsi, the country's first democratically elected leader, following mass protests against his rule.

Friday's attack is the second of its kind near the same monastery within the last year and a half.