Washington: Several persons were injured when an armed assailant opened fire in a gay club in Orlando state of the US early on Sunday, police said. The attacker was still inside the Pulse Club in Florida city and had taken hostages, BBC reported. Orlando Police said they carried out a controlled explosion. According to media reports, at least 20 shots were heard inside the club. The attacker was suspected to have a bomb. More than 100 people were enjoying a Latin-themed night in the club when the shooter opened fire around 2.00 a.m. (local time). "We heard rapid fire go off. In the room I was in, people went down to the floor. I wasn't able to see the shooter or people get hurt," an eyewitness said. The incident comes as Orlando is reeling from the fatal shooting of 22-year-old singer Christina Grimmie following a concert on Friday night. She was signing autographs when Grimmie was shot by Kevin James Loibl, 26, who then killed himself. It is not clear what Loibl's motive was.