A flight headed to Seattle from Reagan National Airport had to make an emergency landing at nearby Dulles International Airport after its pilots reported smoke in the cockpit.
Alaska Airlines spokesman Cole Cosgrove says the flight had just taken off around 10.22am when the pilots "noticed indications of smoke" in the cockpit. The plane landed at Dulles at 10:38am.
Metropolitan Washington Airports Authority spokesman Chris Paolino says six people were taken to the hospital. He says they were all members of the plane's crew.
The Alaska Airlines Boeing 737 was carrying 161 passengers, all of whom were evacuated safely.
Officials say the passengers were rebooked on other flights.
Authorities say the cause of the incident remains under investigation.