PESHAWAR, Pakistan – Mourners poured into the streets of this grieving city Wednesday as families buried children who were slain at a school and Pakistan's prime minister vowed to fight "until all terrorists are defeated."

Pakistan's government lifted a moratorium on executing convicted terrorists and sought Afghanistan's help to find the mastermind of Tuesday's attack on an army-run school as the death toll rose to 144, including 132 children.

In Landi Arbab, a village outside Peshawar, hundreds of mourners gathered to pay respects to Tahira Kazi, the 59-year-old school principal, who was reportedly burned alive by the Pakistani Taliban militants who raided the school.

Family members remembered Kazi as a smiling woman who spoke as much about her students as her own children. But many could not summon the courage on Wednesday to look at her face, which had been burned beyond recognition.

"Her death is a great loss to our village and school," said a second cousin, Kazi Ashfaq, 45. "She was such a committed teacher and a sweet person."

Calls for swift justice against militants reflected the shock and anger reverberating across Pakistan, which has seen thousands of civilians killed in terror attacks in recent years, but never quite so brazenly as on Tuesday.

Prime Minister Nawaz Sharif lifted a moratorium on the death penalty for terrorism cases, paving the way for inmates to be executed by hanging. An estimated 8,000 Pakistani prisoners are on death row.

"We have proposed terror cases should be expedited," Sharif said. "If terrorists are not punished, then who will be punished?"

The insurgent group said the attack was to avenge a Pakistani army offensive in the country's northern tribal areas this year. Sharif pledged to continue the operation, saying, "The time has arrived to finish those who killed my children."

Pakistan's army chief of staff, Raheel Sharif, called on Afghanistan to arrest Pakistani Taliban leader Mullah Fazlullah, who is wanted on terrorism charges in Pakistan and is believed to reside on the Afghan side of the border.

Attack in Afghanistan

The violence continued as suicide bombers attacked a bank in southern Afghanistan on Wednesday, killing at least 10 people, officials said.

The Taliban claimed responsibility for the attack, in Lashkar Gah, the capital of Helmand province. It began shortly after 12 p.m., when a suicide bomber detonated his explosives near the entrance of a Kabul Bank. Three other attackers, all strapped with explosives, stormed inside, said a spokesman for the provincial governor.

The dead included two Afghan soldiers, two police officers and a member of the National Directorate of Security, Afghanistan's main intelligence agency. Five other people died and at least 14 were wounded, officials said.

The New York Times contributed to this report.