Firefighters extinguished a 2-alarm fire burning on the rooftop of a five-story apartment building in Dublin early Saturday afternoon.
Around 12:30 p.m., firefighters responded to a report of a fire in the 5300 block of Iron Horse Parkway, according to Alameda County fire spokeswoman Aisha Knowles.
Firefighters were unable to locate the source of the fire and additional units from the Livermore-Pleasanton Fire Department responded to provide assistance, Knowles said.
Firefighters fully extinguished the fire within about 30 minutes of arrival, according to Knowles.
No injuries were reported as a result of the blaze.
The cause of the fire remains under investigation, Knowles said.