A suicide bomber has killed at least six people in eastern Pakistan, including several soldiers.
Authorities said that a van transporting census officials in Lahore, capital of the country's most populous Punjab province, was the target of Wednesday's attack. The Pakistani Taliban has claimed responsibility for the deadly bombing.
The blast wounded around 20 people. Provincial Minister of Health, Khwaja Imran Nazir, said three of them were in "critical" condition.
“Doctors are operating upon them, and God willing they will recover. The rest of the patients are in a stable condition,” he added.
An eyewitness told reporters he was sitting at home across the street with his family when they heard the blast.
“We came running here and saw bodies of the victims scattered all over while those wounded were crying for help,” the man said.
Counterterrorism officials retrieved body parts of the suspected bomber and an investigation has been launched into the attack, according to provincial police.
Pakistan last month went ahead with its first national census in 19 years, deploying around 120,000 civilian enumerators and 200,000 Pakistani troops to support them. The massive exercise is due to be concluded by the end of May.
The Pakistani Taliban has stepped up attacks in Pakistan since the beginning of this year, killing scores of people.
Islamabad alleges militants are plotting the violence against the country from their sanctuaries inside neighboring Afghanistan, charges Kabul rejects.