OAKLAND -- A two-alarm fire at a vacant one-story home in East Oakland on Sunday morning is being called suspicious by authorities.

The blaze, which started just after 10 a.m., caused the roof to collapse on the single-floor, wooden home located in the 1900 block of E. 17th Street, about a block from San Antonio Park, Oakland Fire Department Battalion Chief Adrian Sheppard said. The home has been vacant for some time, police said, and has been used by squatters.

Nobody was injured, authorities said.

One squatter who witnesses saw at the home shortly before the fire fled the area, police said. Investigators are trying to determine if the fire was deliberately set or started accidentally, Sheppard said.

The second alarm was called to prevent the spread of the fire to apartments on either side of the home, Sheppard said. Police said they evacuated those buildings before fire crews arrived.

The fire damages to the home were estimated at more than $50,000, Sheppard said. Twenty-five firefighters were used, and crews had the fire under control in 40 minutes, Sheppard said.

Contact Rick Hurd at 925-945-4789 and follow him at Twitter.com/3rdERH. Contact Harry Harris at 510-208-6443 and follow him at Twitter.com/HarryHarris15