A Pakistani military helicopter has crashed near Orakzai tribal region in the northwest of the country, killing 26 security personnel.

"An MI-17 helicopter crashed due to technical fault," a military official told Reuters on condition of anonymity, adding 26 that security personnel were killed in the incident.

He said that the site of crash was located 20 kilometers (12 miles) from Peshawar, the capital of North West Frontier Province.

Earlier reports by government officials in the region said five people had been killed in the chopper crash, which occurred on the border of Khyber and Orakzai agencies.

Locals told Press TV correspondent that the copter came under fire by militants on ground.

Pakistan's security officials said they have launched "detailed investigations" into the deadly helicopter crash.