Negotiators for Pakistan's government and the Taliban met for more than three hours Thursday in the first round of talks aimed at ending the militants' bloody seven-year insurgency.

The two sides gathered in Islamabad for a preliminary meeting likely to chart a "roadmap" for future discussions, amid deep scepticism over whether dialogue can yield a lasting peace deal.

Irfan Siddiqui, the government's chief negotiator hailed the meeting after it had finished, saying that the Taliban committee had "responded to us beyond our expectations".

The breakthrough came after an abortive start to the talks Tuesday, which were called off when the government cited doubts over the Taliban negotiating team.

"We are really happy that the Taliban committee has responded to us beyond our expectations and they have heard our reservations and told us their reservations with an open heart," Siddiqi told reporters on Thursday evening.

"We share the common goal of making this country peaceful in accordance with Islamic teaching. And I thank the Taliban committee for meeting us," Siddiqui added.

Maulana Sami-ul-Haq, the Taliban's chief negotiator, said his side would hold discussions with the Taliban leadership and a second round of talks would be held after they had responded.

Fragile security

Underlining the fragile security situation, a suicide bomber on Tuesday killed eight people in a sectarian attack against minority Shiite Muslims in the northwestern city of Peshawar, just hours after the abortive start to the talks.

The main TTP spokesman denied they were behind the blast but a commander for the group in Peshawar told AFP his men were responsible, saying no ceasefire had been announced.

Haq said after Thursday's talks that both sides had condemned the violence and agreed that "there should be no activity by either side which can potentially harm the peace efforts".

The Tehreek-e-Taliban Pakistan (TTP) has killed thousands of people in gun and bomb attacks across the nuclear-armed state since it launched its campaign in 2007.

The start of the year has seen a surge in militant violence with more than 110 people killed, and an air force bombardment of TTP hideouts in North Waziristan fuelled speculation that a major military offensive was imminent.

There is talk of splits within the TTP, a fractious coalition of militant groups, with some rumoured to oppose the whole idea of negotiations.

Saifullah Khan Mehsud, director of the FATA Research Centre, said this made it difficult to achieve even a ceasefire as a first step.

"I don't know if the Taliban are on the same page and which groups that these negotiators are representing, so I don't know if they can guarantee a ceasefire at all," he told AFP.

'Hybrid theocracy'

Stability in nuclear-armed Pakistan is seen as important to neighbouring Afghanistan, where US-led NATO troops are pulling out after more than a decade of war.

Washington has said it is watching the talks closely. It has long been pushing Pakistan to take action against militants using Pakistan's tribal areas as a base to attack NATO forces across the border.

Observers have held out scant hope for the talks, saying there appears to be little common ground and warning of what the government might be forced to concede.

One of the TTP's negotiating team, Maulana Abdul Aziz, told AFP on Wednesday there was no chance of peace unless the government agreed to the imposition of Islamic sharia law throughout Pakistan.

The Taliban also want US troops to withdraw from Afghanistan.

The government has insisted that Pakistan's constitution must remain paramount, but security analyst Ayesha Siddiqa warned they may find themselves forced to give ground.

"I look at history and see that every time the non-religious leadership has tried to do some appeasement Pakistan has slipped deeper into theocracy and this is one such moment," she told AFP.

"We are already a hybrid theocracy and we are heading towards more theocracy."

Local peace deals with the militants in the past have quickly fallen apart.

Government efforts to start peace talks last year came to an abrupt halt in November with the killing of TTP leader Hakimullah Mehsud in a US drone strike.