A fire Monday evening at the Northwest Washington offices of United Palestinian Appeal Inc. has been ruled arson, though police said yesterday there is no evidence the blaze was set by terrorists.

No one was injured in the 7:40 p.m. fire in the fourth-floor offices of the UPA at 2100 M St. NW, police and fire officials said. They said the FBI and the Treasury Department's Bureau of Alcohol, Tobacco and Firearms are assisting in the investigation of the blaze, which caused about $60,000 damage.

Police said they are searching for a "possible suspect" in the arson, and Bishara Bahbah, the organization's director, said he was told by police yesterday that witnesses saw a man running from the building shortly before the blaze was discovered. The UPA is a nonprofit organization "dedicated to alleviating the suffering of the Palestinian people."

"We can't help but think it the fire might be motivated by the fact that we're Palestinians, but we do not know," Bahbah said. He said the fire damaged the office's reception area and destroyed some computers, files and furniture.

On Nov. 29, a fire ruled to be arson at 1729 Connecticut Ave. NW damaged the fourth-floor offices of the American-Arab Anti-Discrimination Committee, prompting an FBI investigation into whether the rights of Arab Americans were violated by a series of attacks against the group's regional offices.