Inferno ... Los Angeles County firefighters battle a fire at an apartment building under construction next to the 110 Freeway. Picture: AP Source: AP

No injuries were reported but the flames near a downtown freeway interchange could be seen for miles and billowing clouds of smoke closed down adjacent highways in two directions.

Massive fires ... Los Angeles County firefighters battle a fire at an apartment building that was under construction next to the 110 Freeway. Picture: AP Source: AP

A seven story apartment building under construction was severely damaged, as were two adjacent office towers, city fire officials said.

A second fire a short drive away also caused severe damage to a building housing apartments and commercial spaces that was under renovation.

Blaze ... Los Angeles County firefighters on the scene as the fire rages in an apartment building that was under construction. Picture: AP Source: AP

Both fires were brought under control.

More than 350 fire fighters were battling the blazes, a quarter of the city’s fire fighting force, Los Angeles Fire Department public information officer David Ortiz told AFP.

“There was a great impact due to both fires on local commute traffic,” Mr Ortiz said.

Hellish ... Los Angeles County firefighters at the scene of the first fire. Picture: AP Source: AP