A man was stabbed and seriously injured Sunday night on the platform at the Ballston Metro station in Arlington , authorities said.
Two men were taken into custody in the 8:40 p.m. incident, and a knife was found, a Metro spokeswoman said.
The victim was taken to a hospital with life-threatening injuries, said the spokeswoman, Morgan Dye. It was not known what prompted the stabbing.
This report has been updated.