Gunmen attacked the offices of an international aid group in northwest Pakistan on Wednesday, killing five people working for the organization, police said.
The attackers hurled grenades during the attack on World Vision, a large Christian humanitarian group, in Mansehra district. The dead were all Pakistanis, said police official Mohammad Sabir.
Islamist militants, who are strong in northwestern Pakistan, will be suspected in the attack.
They have killed other people working for aid groups in Pakistan and issued statements saying such organizations were working against Islam.
Many foreign aid groups have been working in Mansehra district, helping rebuild it after the 2005 Kashmir earthquake.