KOB: Albuquerque firefighters continue to battle a three-alarm fire at a business complex downtown near Mountain and Broadway.

It is unclear what started the fire that was reported around 7:45 p.m. Wednesday, creating a smoke plume visible throughout the metro area.

An employee of the facility says most of the businesses stored paper and cardboard which offered ideal fuel to spread the flames. Twenty-three fire department units were called out to control the blaze.

By 10 p.m., authorities said three quarters of the block-long business complex was ablaze and they were aerially fighting the fire, attempting to redirect the flames.

The department has not let any firefighters inside the structure because they are unsure of its safety.