SAN DIEGO — A two-alarm fire erupted at a warehouse in Sorrento Valley Wednesday morning.

It broke out just after 3:00 a.m. at the sign making company, Above All Advertising in the 6900 block of Corte Sante Fe off of Miramar Road, the San Diego Fire Rescue Department said.

When crews arrived on scene, heavy smoke filled the warehouse making it difficult for crews to find the source of the fire, which turned out to be paper goods stacked in the back of the warehouse, SDFD Deputy Chief Steve Wright said. 

There was also damage to some large printing equipment and machines used to make signs and banners, Wright said. 

No injuries were reported. 

Crews requested more engines around 3:40 a.m. to help douse the flames and firefighters had the blaze under control by 4:55 a.m., authorities said.

The cause of the fire was under investigation.