At least six people, including a firefighter, were killed and 20 others injured after a massive fire broke out late Saturday night at Karachi’s Gul Plaza shopping mall in Pakistan. According to The Express Tribune, firefighting operations were still underway on Sunday.

Rescue officials said the victims died due to suffocation caused by dense smoke inside the building, and the injured, several of whom are reported to be in critical condition, were shifted to Civil Hospital Karachi.