June 25 (Reuters) - Fire investigators in the central California city of Fresno on Wednesday were scrutinizing evidence from two brushfires that erupted downtown this week to see if they are related to a string of blazes believed set by serial arsonists.
The two fires that broke out downtown on Monday night were set within minutes of each other, and brought the total in Fresno since May to 23 or more, according to the Fresno Fire Department.
Investigators are examining possible ties between the two fires, both apparently set on freeway shoulders near highways 180 and 99 in downtown Fresno, said Don MacAlpine, deputy fire marshal for the Fresno Fire Department. They are also looking to see if the two blazes are connected to the earlier string of fires, he said.
"We have more than one suspect and we're analyzing that information and looking for common denominators in the various calls," MacAlpine said. "Because we have a higher frequency of these occurring, we're treating all of them as criminal until we rule it out otherwise."
The Fresno Bee reported that two more fires also broke out in the area around the same time as Monday's blazes.
Most of the fires under investigation have been set in unoccupied buildings, officials have said.
"There have been a series of moderate to mild injuries, but nothing of major significance," MacAlpine said. (Reporting by Madeleine Thomas in Berkeley, Calif.; Editing by Sharon Bernstein)