ISLAMABAD: A Pakistani helicopter crashed on Friday in Orakzai, in the northwest tribal belt, killing at least 26 peeople, an official said.

"An MI-17 (military) helicopter crashed due to a technical fault this afternoon at the border of Orakzai and Khyber agency. Twenty-six security personnel on board were killed," the official said.

"This was a utility helicopter. Because of technical faults, it crashed in Orakzai agency," military spokesman Maj.-Gen. Athar Abbas said. Fighter jets have been pounding suspected insurgent hide-outs in South and North Waziristan, where the military says it is preparing for a full-scale offensive against Pakistani Taleban.

Meanwhile, 17 militants were killed and 27 others wounded in a US drone attack on Taleban warlord Baitullah Mehsud's hide-out and a madrassa used to train militants on Friday, sources said.

The attack took place as US Homeland Security Secretary Janet Napolitano met government officials in Islamabad. She discussed topics of "mutual interest" with them, a US Embassy spokesman said.

The United States, facing a growing Afghan insurgency, began stepping up drone attacks on militant strongholds over the Pakistani side of the border a year ago despite Pakistani complaints.

In one attack on Friday, two missiles struck an abandoned seminary in the village of Mantoi that was being used by militants from Mehsud's group for training, the officials said. In the other strike, one missile hit an insurgent communications center in the nearby village of Kokat Khel, they said.

In total, 17 people were killed and 27 others were wounded, they said. "The missiles hit an office of Mufti Noor Wali, who was once in charge of training militants for suicide attacks," one of the officials said.

It was not known if Wali was among the dead, or if any foreign militants had been killed, they said.

— With input from agencies