Dozens of militants armed with rocket-propelled grenades and automatic weapons have attacked two tribal police posts in north-west Pakistan, killing two policemen.
Twenty-one other policemen are missing and presumed kidnapped.
Officials say the attacks occurred before dawn in the town of Darra Adam Khel in Khyber Pakhtunkhwa province. The town is located near Pakistan's tribal region, the main sanctuary for Taliban militants in the country.
The officials say security forces have launched an operation to try to recover the 21 missing policemen.
No group has claimed responsibility for the attack. Suspicion is likely to fall on the Pakistani Taliban, who have been waging a bloody insurgency against the government.