A man set himself on fire outside the UN headquarters in New York on Thursday evening after placing a Tibetan flag on the sidewalk near the complex, according to local media.
The incident occurred at around 7 pm local time (2300GMT) near East 43rd Street and First Avenue.
The man was seen on UN surveillance footage placing the flag before setting himself on fire.
He was taken to Bellevue Hospital in critical condition.
Papers found at the scene reportedly bore the message, "China Out of Tibet."
Police launched an investigation into the incident, while the Tibetan flag remained at the scene for about an hour afterward.
