Pakistan's Prime Minister Nawaz Sharif. Picture: S Sabawoon

Islamabad - Pakistan's Prime Minister Nawaz Sharif condemned as “heinous” on Monday the alleged execution of 23 kidnapped soldiers by the Taliban, casting an uncertain peace process with the insurgents into doubt just two weeks after talks began.

A faction of the Tehreek-e-Taliban Pakistan (TTP) from the northwestern Mohmand district claimed on Sunday night that they had killed 23 paramilitaries who they seized nearly four years ago near the Afghan border.

“Such incidents have an extremely negative impact on the ongoing dialogue aimed at promoting peace,” Sharif said in a statement issued by his office.

A four-member government negotiation team immediately pulled out of peace talks with their Taliban counterparts scheduled for Monday in the northwestern town of Akora Khattak.

Sharif said that Pakistan “cannot afford such bloodshed” and lamented that previous attempts to start dialogue were “sabotaged whenever it reached an encouraging stage”.

He announced the start of talks with the Taliban on January 29 to “give peace another chance” following a seven-year insurgency that has claimed nearly 7 000 lives.

Observers says the two sides are far apart on crucial issues and some experts doubt whether Taliban leaders are able to control the whole organisation, in which some factions are believed to be opposed to peace.

Excluding the soldiers, about 60 people have died in Islamist-linked violence since the talks began.

Government negotiators declared Monday's scheduled talks to be “purposeless” after the “sad and condemnable” murders.

“We regret to say that things are not moving in a right direction,” chief government peace negotiator Irfan Siddiqui said in a statement.

He added that a meeting would be convened on Tuesday to discuss the future course of action.

The disappearance of dozens of Pakistani soldiers was reported by AFP from the Mohmand tribal district on June 17, 2010.

Dozens of paramilitary soldiers from the Frontier Corps vanished after the Taliban attacked their checkpost in a remote area of Mohmand near the Afghan border.

The killing of the prisoners was to avenge the alleged extra-judicial murder of comrades in government custody, the Taliban faction in Mohmand said in its statement sent to AFP late on Sunday.

Peace negotiators nominated by the insurgents said that they regretted that Monday's talks in Akora Khattak had been cancelled.

“The two committees should have sat together and it would have enabled them to find ways to prevent the recurrence of such incidents in future,” the head of the Taliban committee, Syed Yousuf Shah, said from the town.

“We were close to reaching an understanding on ceasefire but it is sad that the government committee called off meeting after considering us as Taliban,” he added at a televised press conference.

The Taliban's demands include the nationwide imposition of sharia law, an end to US drone strikes and the withdrawal of the army from northwestern tribal regions - conditions the government and army are unlikely to be able to meet.

Pakistani troops have for years been battling homegrown insurgents in the tribal belt, which Washington considers the main hub of Taliban and al-Qaeda militants plotting attacks on the West and in Afghanistan.

Nearly 7 000 people have been killed in the TTP insurgency since it began in 2007, according to an AFP tally.

A Pakistani security official, talking to AFP on condition of anonymity, denied that insurgents had been killed in custody as claimed by the Taliban in Mohmand.

“The killing of terrorists in the custody of security forces as alleged by the TTP is a baseless allegation and is a mere propaganda to justify their dastardly acts of terror,” the source said.