An on-duty Montgomery County police officer suffered a fatal gunshot wound Monday in downtown Silver Spring, but the circumstances of the incident remained unclear, authorities said.

“We’re looking at all options with regard to this investigation,” said Marcus Jones, the acting Montgomery police chief, who identified the officer as Thomas J. Bomba, 38, a member of the force for 13 years.

“We are treating this as a homicide . . . until we have information to suggest otherwise,” Jones said at an afternoon news briefing.

Although police did not immediately find any conclusive evidence that Bomba died of a ­self-inflicted wound, Jones said, they also had “no suspect information” or any reports from the public about suspicious activity in the area.

Jones said Bomba made a radio call reporting “disorderly subjects” on the roof of a parking garage near Ellsworth Drive and Fenton Street in Silver Spring about 8:50 a.m. There was no additional communication from Bomba, police said. Within a few minutes, officers who arrived as backup found that Bomba had been shot, Jones said.

Bomba, a married father of two who lived in Gaithersburg, was later pronounced dead at a hospital.

“We continue to investigate this event and we will do everything in our power to ascertain what transpired,” Jones said, adding, “We do not believe at this time there is an immediate threat to public safety.”

He said police found no weapons at the scene except for the officer’s gun. Asked whether the gun had been fired, he said, “We’re looking into that.” As for Bomba’s body-worn camera, Jones said, “We are looking at that evidence now to see if the body camera was on and whether it was functioning at the time.”

He said investigators also were trying to locate all security cameras in the area. At Monday’s afternoon briefing, he said they had not seen any video yet that shows possible suspects or offers a clue of what happened.

While the investigation continued Monday, a heavy police presence in the area caused some road closures. Schools in the vicinity were told to shelter in place, but the precaution was later lifted.

“Our prayers are with his family, the Montgomery Co. Police, Fire and Rescue community, & with all those who serve & protect our communities,” Maryland Gov. Larry Hogan (R) said on Twitter. “We will continue to monitor the ongoing investigation.”

Montgomery County Council President Nancy Navarro (D-District 4) expressed the council’s “deepest condolences,” asking the public to “please keep Officer Bomba and his family in your thoughts and prayers.”

Added County Executive Marc Elrich (D), “Our county lost one of our own, and I ask the people of Montgomery County to keep Officer Bomba’s family, his friends and fellow officers in your hearts during this very difficult time.”

Justin Wm. Moyer, Rebecca Tan and Rachel Chason contributed to this report.