Five people are dead after suspected Islamist militants attacked the office of U.S.-based Christian aid agency World Vision in Pakistan on Wednesday.

Gunmen burst into the office in Mansehra, 40 miles north of Islamabad, at about 9 a.m.

Police say the attackers entered the building, set off a bomb and then opened fire.

Police are criticizing World Vision's security and said they did not have proper security arrangements and had just one guard who was unarmed.

Mansehra has been a hub for relief efforts following an earthquake that killed 73,000 people in October 2005.

The area has been generally peaceful although there have been occasional incidents of violence.