Pastor William Siraj died instantly in the ambush, church authorities said.

No one immediately claimed responsibility for the shooting in a city where a twin suicide bombing killed scores of people outside a church in 2013 - one of the deadliest attacks on the country's Christian minority.

Azad Marshall, the most senior bishop in the protestant Church of Pakistan, condemned the attack and tweeted: "We demand justice and protection of Christians from the Government of Pakistan."

Pakistan's northwestern areas bordering Afghanistan have seen a rise in militant attacks on security forces in recent days, most of them claimed by Tehreek-e-Taliban Pakistan (TTP), a group which associates itself with the Afghan Taliban.

The attackers opened fire on the car carrying Pastor Siraj and the Rev Patrick Naeem in the city's Chamkani area, church officials said.

Naeem was out of danger and being treated, a spokesman for the city's Lady Reading hospital said.

Bishop Azad said both were clergy of the Diocese of Peshawar in the Church of Pakistan, which is a union of protestant churches including the Methodists and the Anglicans.