Aircraft from Afghanistan killed as many as 18 people after firing two or three missiles into a village stronghold of pro-Taliban Islamists in Pakistan early today.
A Pakistani military spokesman said the attack happened in the Bajaur tribal region, which border's Afghanistan's Kunar province - an area not accustomed to insurgent violence.
Bajaur is part of Pakistan's long, rugged tribal belt bordering Afghanistan.
The nearby Waziristan tribal region has been the scene of clashes between security forces and al-Qaeda militants for more than two years, but there have been no previous reports of fighting in Bajaur.