PESHAWAR, Pakistan (AP) — Militants attacked a health center used in an ongoing anti-polio campaign in northwestern Pakistan on Tuesday, triggering a shootout that left two police officers dead, local authorities said. Three of the attackers were also killed in the exchange of fire. No one immediately claimed responsibility for the attack in Orakzai, a district in Khyber Pakhtunkhwa province and a former stronghold of the Pakistani Taliban.

Local police officer Adnan Khan said the attack happened in the morning as health workers were gathering ahead of leaving for the door-to-door campaign along with police, who escort polio teams for their safety. No polio worker was harmed in Tuesday's attack but another police officer who was wounded later died at a hospital, Khan added. The attack drew condemnation from the country's top political leadership, including President Asif Ali Zardari and Prime Minister Shehbaz Sharif, who paid tributes to the slain officers for bravely responding to the attack.

Also Tuesday, militants stormed a health center in North Waziristan, another former stronghold of the Pakistani Taliban in Khyber Pakhtunkhwa, snatched guns from officers and warned health workers who had gathered there not to take part in the anti-polio campaign, local police officer Shoib Khan said. The attackers then left with the weapons they seized, he said, without offering more details. Militants in Pakistan often target police and health workers during campaigns against polio,.