A Pakistani minister said investigators have concluded a deadly explosion the previous day in the city of Lahore was caused by a gas leak from a cooking cylinder - not a bomb as stated earlier by officials.

The explosion killed at least seven people in a posh area of the eastern city and was caused by a bomb planted at the market, multiple police and administration officials said on Thursday.

But authorities revised their assessment at a press conference in Lahore on Friday.



"Yesterday's explosion was an accident. It was not caused by explosives or a result of terrorism," Punjab's Law Minister Rana Sanaullah said.

"The presence of gas cylinders and leakage has been confirmed on the site. We got the forensic report this morning and the results and conclusions are that there was no indication of explosives or related materials."

Sanaullah blamed the confusion on chaos in the aftermath of the incident.

Reports of a second blast in the Gulberg area were later retracted by government officials, who said a tyre blowout caused the loud sound.

The incident underscored growing nervousness across the country after a series of assaults shook Pakistan after a prolonged lull in violence.

On February 17, Pakistan suffered the deadliest attack in more than two years as a suicide bomber killed at least 88 people and wounded hundreds at a Sufi shrine. The Islamic State of Iraq and the Levant (ISIL, also known as ISIS) said it was behind that attack.

Jamaat-ul-Ahrar, a Pakistani Taliban-linked armed group, claimed responsibility for last Monday's suicide attack targeting police at a protest rally in central Lahore. At least 13 people died in the blast.

Government and military officials have vowed extensive operations to hunt down attackers across the country, and Pakistan's border with Afghanistan has been shut down because of security concerns.

After the shrine bombing, Pakistani security forces said they had killed more than 100 suspected fighters in targeted campaigns across the country.

On Wednesday, Pakistan's army announced it was launching a new military operation in response to recent violence.

Dubbed Radd-al-Fasaad, the operation by paramilitary forces is taking place in Punjab, Pakistan's most populous province with Lahore its capital.

The operation aims to provide "more effective border security", a military statement said.