LONDON, England (CNN) -- A fire raged for hours in central London Wednesday, sending black smoke high into the air over the city.
Benjamin Funk was standing on the roof of the Tate Modern museum when he spotted smoke rising.
Twelve fire engines and 60 firefighters are on the scene, which is about half a mile west of St. Paul's Cathedral, a London Fire Brigade spokeswoman told CNN.
There were propane tanks on the roof of one of the buildings when the blaze broke out, but they were moved for fear they would explode if the flames reached them, CNN's Atika Shubert reported from the scene.
"We believe the fire is at the fifth floor and the roof on one building," the fire department spokeswoman said. "We were called at just before 3:40 p.m. (11:40 a.m. ET)." The fire was still burning nearly three hours later.
There are no reports of injuries, and firefighters believe they are getting the blaze under control, she added.
Firefighters were attempting to douse the fire with water from above, video from the scene showed. Watch footage of the fire »
The fire started in a building under construction and spread to a neighboring building, firefighters said. People have been evacuated from the buildings, police said, and they do not believe anyone is in danger. iReport.com: Witness the fire? Share photos, video
The fire is just north of the Royal Courts of Justice, and near the Maughan Library of King's College London, which houses the college's rare books collection. The library occupies the Victorian former Public Record Office building on Chancery Lane. Neither the library not the courts are on fire.
CNN's Per Nyberg, Claudia Rebaza, Laura Perez Maestro and Alysen Miller contributed to this report.