San Diego:  Police have arrested a woman who held a gun to her head and fired off rounds in a carpark in downtown San Diego, not far from an annual marathon that was well underway on Sunday, authorities said.

The incident began shortly before 11am, local time, as a call about a misdemeanour hit and run, Sergeant Tom Sullivan said. Officers later found a woman underneath a parked car on the carpark's 8th level, Sullivan told the Union-Tribune . She was taken into custody after she fired several shots, he said.

A number of surrounding streets were closed as officers responded in the area near City Hall. Police didn’t immediately say if there were any injuries.

The shooting was near the finish line of the San Diego Rock ‘n’ Roll Marathon. The incident halted the race for about 10 minutes as police investigated, marathon officials said.

Several runners said they had already completed the race before the incident and the run was not interrupted.