"It was a bomb blast with a huge sound impact that smashed the windows of almost all the buildings around," said Punjab government spokesman Malik Mohammad Khan. He said the blast caused a huge crater and authorities were investigating the exact "nature and motives" of the blast. Punjab police spokesman Nayab Haider said the explosion was caused by a bomb that was detonated either remotely or by timer. Pakistan has been struck by a wave of militant attacks in recent weeks which have killed at least 130 people.
One attack at a Sufi shrine in southern Sindh province killed 90 people. Rescue officials said security forces cordoned off the site of Thursday's blast, in a residential neighborhood which also houses banks and coffee shops, after what one bank worker described as a frightening explosion.
"We left the building and saw that the motor-bikes parked outside were on fire and all the windows in the surrounding buildings were shattered," eyewitness Mohammad Khurram told Reuters. Reports of a second explosion in the city turned out to be a tire blow-out, a government official said. Thursday's bombing was the second attack in Lahore in two weeks. A suicide bombing on Feb. 13 killed at least 13 people at a protest near the provincial assembly. Government and military officials have vowed to hunt down militants across the country and Pakistan's border with Afghanistan has been shut down due to security concerns. After the shrine bombing, Pakistani security forces said they had killed more than 100 suspected militants in targeted campaigns across the country.