Police say a roadside bomb has exploded near a vehicle carrying security forces in restive northwestern Pakistan, killing four officers and wounding five others.

Pakistani officials say militants attacked a health center used in an ongoing anti-polio campaign in the country's northwest, triggering a shootout that left two police officers dead.

Two Pakistani terrorists were killed in separate encounters with security forces in North Kashmir's Bandipora and Kupwara districts. The operations were part of an intensified crackdown following a recent surge in terrorist attacks.