Portions of two major freeways in downtown Los Angeles were closed after a huge fire broke out in a seven-storey, under-construction building. Over 250 firefighters were present at the location to douse the mammoth blaze, which started early Monday.

The fire began at 909 West Temple St., a 1.3 million square foot mixed-use complex, and was reported at about 1:20 a.m. local time (4:20 a.m. EST), NBC News reported, citing David Ortiz, a spokesperson for the Los Angeles Fire Department (LAFD) adding that nobody was inside the building when the fire broke out.

"Large windows gave under the amount of heat," Fire spokesman Jaime Moore reportedly said, adding: "Sprinklers activated on 6 floors. There was active fire on three floors."

The California Highway Patrol issued a SigAlert to shut down transition lanes between the 110 and 101 freeways along with several surface streets. The cause of the fire was not clear and there were no injuries so far, the Los Angeles Times reported, citing Ortiz.

Two other buildings on nearby Figueroa Street suffered damage from the fire, while a building at 331 N. Figueroa St. suffered "external damage from radiant heat," according to the LATimes. Several floors at an office tower at 21 N. Figueroa St. were also damaged by the fire.

Officials, who said that the fire was burning wood framing in the new building, expect to be able to clear the freeways by 5 a.m., NBC reported, adding that the smoke could be seen for miles from the building.

Residents in the area took to social media to express their concern.

Meanwhile, the LAFD advised media to only take aerial pictures due to the dangerous situation at the location.