Update | Inferno in the streets as suspected gas explosions kill 24, injure 271 in Taiwan's Kaohsiung

At least 24 people were killed and 271 others injured when several underground gas explosions ripped through Taiwan’s second-largest city overnight, hurling concrete, parked scooters, even injured victims through the air and blasting long trenches in the streets, authorities said on Friday.

The series of explosions about midnight on Thursday and early on Friday struck a district where several petrochemical plans operate pipelines alongside the sewer system in Kaohsiung, a southwestern port with a population of 2.8 million people.

The fires were believed to be caused by a leak of propene, a petrochemical material not intended for public use, but the source of the gas was not immediately clear, officials said.

Watch: Multiple gas explosions in Taiwan's Kaohsiung streets

Video from the TVBS broadcaster showed residents searching for victims in shattered storefronts and rescuers pulling injured people from the rubble of a road and placing them on stretchers while passers-by helped other victims on a sidewalk. Broadcaster ETTV showed rows of large fires sending smoke into the night sky.