Gunmen have attacked a bus carrying Coptic Christians in central Egypt, killing at least 28
The Copts killed had been travelling to St Samuel's monastery to pray
Between eight and 10 gunmen wearing military uniforms attacked the convoy
According to The New York Times, the gunmen ordered the passengers to get out of the bus
They told the men to recite the shahada, the Islamic declaration of faith
When the men refused, the gunmen opened fire
There was no immediate claim of responsibility
