MARC train riders walk to catch a Brunswick line train at the Olde Towne Gaithersburg station. (Anthony Castellano)

Montgomery County police have begun an investigation into an incident in which an officer’s police vehicle was struck Monday morning by a MARC train as he attempted to cross the tracks in North Bethesda.

No injuries were reported, but several hundred passengers on the eastbound train were stranded on board for over an hour, officials said. Those waiting to board at the nearby Rockville station had to be diverted to Metro.

Police spokesman Paul Starks said the officer was responding to an emergency call when he inched his squad car up to the edge of the tracks near the intersection of Randolph Road and Nebel Street. The train clipped the car’s front bumper when it passed.

“It didn’t sound like the usual thud, like if we had hit a deer,” said MARC passenger Gene Hayes. “It was very metallic.”

The train’s front car suffered some damage, according to MARC spokesman Terry Owens, but was able to return to the rail yard under its own power.

The name of the officer involved in the accident was not immediately available.

Starks said the officer had his siren on as he responded to a 911 call, made by a woman who said she was in imminent danger. Officers later determined that the woman, who suffers from a mental illness, had imagined the threat.

“But we didn’t know that at the time,” Starks said, explaining why the officer might have been tempted to cross the tracks ahead of the train. “We don’t have the option to get lunch first,” Starks said.