By M Ilyas Khan
BBC News, Islamabad
The strikes follow a suicide attack on soldiers in Hangu
Army jets and helicopters have launched air strikes on a number of militant sites in north-western Pakistan, officials say.
The strikes in the Orakzai tribal region come a day after a suicide car bombing killed more than 20 soldiers in nearby Hangu district.
A key deputy of leading militant warlord, Baitullah Mehsud, is said to be based in Orakzai.
The deputy, Zulfiqar Mehsud, had said he carried out the Hangu attack.
The casualties in the Orakzai strike are unclear.
An army spokesman contacted by the BBC confirmed the strikes in the Afghan border region but had no details on casualties.
An army official told the Reuters news agency at least 20 militants had been killed when jets and helicopter gunships hit their hideouts in the Ghaljo area of Orakzai.
A suspected US drone also targeted Orakzai three weeks ago, killing more than 10 suspected militants.
Zulfiqar Mehsud is reported to have been involved in disrupting supplies to Nato in Afghanistan from his bases in Orakzai.
He claimed responsibility for the suicide car bombing of a security checkpoint in Hangu on Saturday.
On Sunday a suspected US drone missile targeted militants in South Waziristan, where Baitullah Mehsud is said to be based.
The attack was reported to have killed three people in the Zari Noor village area.
Baitullah Mehsud claimed responsibility for last month's attack on a police academy in the eastern city of Lahore in which eight people were killed.
He was also accused by the government of planning the 2007 assassination of former PM Benazir Bhutto, a charge he has denied.
The US believes South Waziristan and the tribal regions are a haven for Taleban and al-Qaeda fighters who enter Afghanistan to fight US and Nato forces.