WASHINGTON (Reuters) - A head-on collision between a shuttle bus carrying Chinese tourists and a passenger car killed a bus passenger and injured 15 people outside Washington, D.C., police said on Wednesday.

The bus with 19 Chinese tourists tipped onto its side during the Tuesday accident on the George Washington Memorial Parkway in northern Virginia, the U.S. Park Police said in a statement.

One tourist was killed and 13 bus passengers and the car's driver and its passenger were taken to hospitals, two in critical condition, police said. The bus driver was not hurt. The accident is under investigation.

Passersby, some possibly with the military, stopped at the accident site to right the bus and administer first aid, police said.

"We are currently following several leads into identifying these heroic people," they said.

(This story has been refiled to correct typographical error in headline to 'bus')

(Reporting by Ian Simpson; Editing by Toni Reinhold)