Montgomery County Police Chief Charles A. Moose has been called up by the National Guard to help oversee security either at Andrews Air Force Base or closer to the fighting in Iraq, according to county police and Guard officials.

Moose, a major who commands the 113th security forces squadron in the District of Columbia Air National Guard, was mobilized about 4 p.m. Tuesday and ordered to Andrews Air Force Base pending further word on deployment, police and Guard officials said yesterday.

"We don't know whether he's going to be here or over there," said Staff Sgt. Sophia Piellusch, a spokeswoman for the D.C. Air National Guard. She said it was not clear yesterday afternoon whether the entire unit or just some members had been activated.

County Executive Douglas M. Duncan (D) appointed William O'Toole, one of three assistant chiefs on the force, as acting chief in Moose's absence yesterday.

Moose, who was the chief of police in Portland, Ore., before assuming the chief's job in Montgomery in August 1999, served in the Oregon Air National Guard from 1987 to 1998, officials said.

About two dozen police officers on the 1,020-member Montgomery force are reservists, and fewer than a dozen had been mobilized as of the first week of March, police spokeswoman Lucille Baur said yesterday.

Montgomery's Fire and Rescue Services also has about a dozen reservists who have been called to duty from the ranks of approximately 2,000 firefighters in the career and volunteer force, said spokesman Pete A. Piringer. None in the top echelon of the career ranks has been called so far, he said.