A man was stabbed Tuesday evening on the platform of the Van Ness Metro station after a dispute with a woman, authorities said.

The 56-year-old man was stabbed in the left side in the lower part of his abdomen about 4:45 p.m. and was taken to a hospital. He was conscious and alert when transported and his injuries did not appear to be life-threatening, authorities said. The man was to be held overnight, said Metro spokesman Dan Stessel.

His assailant, a woman who appeared to be in her 20s, left the station without being stopped and was at large Tuesday night, Stessel said. Metro said that a knife was used in the attack but that it has not been found.

Although both had just exited a train that was headed downtown, they did not know each other, Stessel said. The subject of the dispute was not immediately known.

The stabbing was reported shortly before 5 p.m., a time when ridership in the Metro system is typically heavy. However, Stessel said, the Van Ness-UDC station “was not particularly busy” at the time of the attack.

Police released this photo of a female suspect in a Tuesday stabbing at the Van Ness Metro station. (Courtesy of Metro Transit Police)

He said the man went up the escalator under his own power and reported the incident to the station manager. The woman, who carried an umbrella shown in surveillance camera footage, also went up an escalator and out, Stessel said.

It was not known where each had boarded the train.

Service on the Red Line, which runs through Van Ness, was not affected, Stessel said.