ALAMEDA — Firefighters on Thursday morning responded to seven fires that they described as suspicious, including one that broke out in a cage storing cardboard for recycling at Alameda Point and spread into an adjacent building.

No one was hurt during the fires, which caused no significant damage, Alameda firefighter Juan Medrano said.

Four engines, two ladder trucks and two medical units were dispatched at 3:44 a.m. to the 1800 block of Ferry Point, where the fire that began in the recycling cage had spread up the wall of the building and into the structure, activating its sprinkler system.

Firefighters forced their way into the building to fully extinguish the fire, Medrano said.

The building houses Alameda Point Studios, which has light industrial workshops and tenants who include furniture makers, printers, piano restoration specialists and metal workers.

Four other outside fires were reported within a four block radius about the same time as crews were extinguishing the fire at the building on Ferry Point. Incoming engine companies were diverted to those fires and extinguished them before they could grow larger.

Additional smaller fires were reported until about 7:30 a.m., Medrano said.

Each of the fires is suspicious and the causes remain under investigation, he said.

Reach Peter Hegarty at 510-748-1654 or follow him on Twitter.com/Peter_Hegarty.