Shalini Doal, who works nearby, told the BBC she saw the emergency response when she finished her shift at about 22:00 on Friday.
She described the scene has “quite chaotic”, and same some of her colleagues heard a commotion at about 21:00.
“A lot of my colleagues take public transport, take the tram… our safety is at risk essentially, here in the city centre.”
Ashley Birks, 25, from Stoke-on-Trent, said he came to Birmingham fairly regularly to see his girlfriend who lives in the city, and was concerned about what had happened.
“It makes me worried for my girlfriend,” he said.
“She doesn’t drive and works at all of the big music venues… and to think something completely unprovoked [happened], you know, it’s horrible.”
