Firefighters are tackling a massive blaze in Leicester. Flames can be seen leaping from the roof of the Curzonia Knitwear factory in Birstall Street, off Dysart Way, St Matthews. Thick, black smoke from the fire is drifting across the city. The huge blaze is believed to have started at Cloud 9, a shisha bar which was built on the roof of factory. Workers in the knitwear factory were evacuated after the alarm was raised. The fire service has confirmed six crews are at the scene. Paramedics are also at the scene. Birstall Road has been cordoned off, with police re-directing traffic along alternative routes. Area Traffic Control has also said that Syston Street, East, Curzon Street and Cobden Street are also closed. An eyewitness, who watched the drama unfold from her living room window, said: "I saw it start and it got huge so quickly. "I thought it might start to spread, but the fire service and police cordoned off the roads around it. Houses like mine are pretty close though. "It's worrying because there is a petrol station next to it and an old people's home opposite." Pakeer Suleiman, who runs photography business Creating the Memories, in nearby St Saviours Road, said: "It was massive, there was black smoke filling the sky." Aaron O'Connor, landlord of the Durham Ox pub, which sits next door but one to the factory, said: "I've had loads of messages on Facebook from people worried it was the pub on fire so I've had to reply and assure them we're okay. "I first saw it when the cleaner grabbed me and told me about all the smoke and flames. "There was thick smoke everywhere - it was coming from the roof. "I wasn't sure if it was going spread but there's always that danger."