Nearly 30 people were killed and many others were injured Friday night when an explosion abruptly rocked a nightclub in Romania's capital, UPI quoted authorities as saying. The blast hit the Colectiv club in downtown Bucharest, where hundreds of people had gathered to watch the rock band Goodbye to Gravity perform. According to witnesses, the fiery explosion occurred while the band was on stage and was in the middle of a pyrotechnics display that may have sparked the flames. An explosion followed a few seconds after the fire erupted, the witnesses said. A member of the band, Lemi Black, said he saw two foam pillars catch fire -- followed quickly by a stampede for the door. As many as 400 people were inside the club when the fire occurred, and many were unaccounted for as fire officials worked at the scene. Romanian Interior Minister Gabriel Oprea said at least 27 people were killed and 180 were injured. Officials reportedly said the death toll could go as high as 40.