Residents of Pakistan's ethnic Pashtun region of North Waziristan accused government troops on Monday of killing dozens of civilians during a military operation against Taliban insurgents.
The operation started just after a December 18 suicide bomb attack on a checkpoint in North Waziristan, a stronghold for al Qaeda-linked Taliban militants on Pakistan's mountainous border with Afghanistan.
Speculation that the army might launch a major offensive in the frontier tribal areas has been building as the government's attempts to engage the Pakistani Taliban in peace talks have floundered in recent months.
Military officials said at least 23 militants had been killed in clashes with security forces in the Mir Ali region of North Waziristan following the suicide attack.
Pakistani authorities imposed a curfew across the lawless region and residents said many people had fled from their homes after days of shelling and raids by helicopter gunships.
Resident Muhammed Tayyab said he lost three of his children and his wife in the shelling.
"On the first day of the attack an artillery shell hit the room where my kids and wife were sleeping," Tayyab told Reuters by telephone. "The government has put them to sleep forever."
Residents put the civilian death toll at several dozen.
"From the first day of the attack until now 70 civilians have been killed," said a tribal elder in Mir Ali who declined to be identified for fear of state reprisals.
"Some truck drivers and hotel and shop keepers were shot directly, and dozens were killed by gunships, mortars, and artillery shelling on the civilian population."
The army did not respond to Reuters telephone calls and text messages requesting a comment on the allegations of civilian deaths in North Waziristan.
Reports from North Waziristan are hard to verify independently because journalists and observers are not allowed to work on the ground in the heavily militarized region.
The Pashtun lands along the Afghan border have never been brought under the full control of any government.
Taliban commander Hafiz Gul Bahadur said insurgents would respond by launching a full scale counter offensive on army positions if attacks against civilians did not stop on Monday.
Residents said bodies were left in the open in the villages of Mosaki and Hasukhel as terrified villagers fled the area.
"We are moving our families to keep them safe but the army's mortars and shells are following us," said Asad Sher of Mir Ali. "Please tell us where is safe. The army is demolishing our homes and bazaars."
Malik Gul Salehjan, another man, said: "My children are asking me for bread but I am not able to give them anything because there is nothing in my house."
A North Waziristan administration official said tribal elders and army representatives convened a jirga, or meeting, on Monday to try to find a negotiated end to hostilities.