At least five people were killed and 20 others injured in an explosion inside a multi-storey building in Pakistan's southern port city of Karachi on Wednesday morning, rescue workers said.
The injured including women have been shifted to different hospitals and five to seven out of them are in critical condition, Faisal Edhi, head of rescue organization Edhi Foundation told Xinhua, adding that two of the killed were security guards of a bank located inside the building.
The explosion happened at about 9:30am local time at the first floor of the building with both commercial and residential settlements, an eyewitness told Xinhua, adding that the impact of the blast was so strong that it not only destroyed the first and ground floor of the building, but also broke glass windows of nearby buildings.
"It was a big bang which was heard even miles away from here (blast site)," the eyewitness said, adding that cement blocks and bricks from building scattered everywhere following the blast which hit the vehicles and motorbikes parked outside the building, damaging many of them.
Talking to media, Sohail Rajput, the commissioner of Karachi, said the bank located at the ground floor of the building also got destroyed in the blast, and its manager reported that one of his employees is still missing after the explosion.
He said they had called in rescue teams with advanced machinery to search for the employee and other possible missing people from the debris of the partially destroyed building, adding that the building is no more suitable for living and will be demolished after completion of rescue, clearance and investigation process.
The nature of the blast has not been determined yet and the bomb disposal squad and officials from natural gas provider company also reached the site.
While the bomb disposal squad has not presented its report yet, the gas authorities said all gas pipelines of the building are safe and there is no trace of any gas leakage.
Meanwhile, the local police issued a statement saying that the blast happened due to explosion of a gas cylinder inside the building, but it was later withdrawn when a police official of the area told media that they are trying to determine the cause as the impact of a cylinder explosion is not as huge as Wednesday's blast.