Islamabad - The death toll from a massive car bombing in Pakistan's north-western city of Peshawar has reached 106, with some shredded body parts still to be labelled, officials said on Thursday.

The explosion ripped through a teeming market for women Wednesday afternoon shortly after US Secretary of State Hillary Rodham Clinton kicked off her first official visit to Pakistan aimed at bolstering ties with the frontline ally in the global anti-terror fight.

Hospital authorities confirmed on Thursday that 106 blast victims had died and up to 40 others were undergoing treatment.

"Thirteen people among the injured are struggling for life," said Abdul Hameed Afridi, head of the city's state-run Lady Reading Hospital. "We have still to label some severed, charred remains of blown-up victims."

The bomb destroyed scores of shops in the congested streets, trapping many in the smouldering rubble whereas a few buildings collapsed as firemen doused the flames.

Rescue workers were searching through the debris on Thursday, looking for bodies or any survivors.

The shopkeepers claimed they had received threats about a possible strike through cellphone text messages.

We were asked by the militants to forbid women from visiting the market, the Urdu-language Mashriq newspaper quoted local trader leader Tauseef Ahmad as saying.

United Nations Secretary-General Ban Ki-moon condemned the attack, saying: "No cause can justify such inhuman and indiscriminate violence."

The bombing, deadliest in Pakistan since 2007, was the latest in a string of attacks by Taliban militants on a range of targets, including UN offices, an Islamic university, police establishments and even the Pakistani army's nerve centre.

Pakistani security forces launched a large-scale offensive to eliminate the Taliban and al-Qaeda network in the South Waziristan tribal region on October 17, saying 80 per cent of terrorist assaults taking place across the country originated from the tribal badlands.

Government officials say the revenge strikes by militants only strengthened their resolve to defeat the militancy.

"We will not buckle. We will fight you," Pakistani Foreign Minister Shah Mahmood Qureshi told reporters in a joint press conference with Clinton in Islamabad Wednesday.

"You are on the run and we know that," Qureshi said.

Clinton termed the Peshawar attack "cowardly," and pledged US support to the counter-terrorism initiates.

"These extremists are committed to destroying that which is dear to us as much as they are committed to destroying that which is dear to you and to all people. So this is our struggle as well," Clinton said.