A Dallas-bound flight was diverted to the Albuquerque International Sunport after smoke filled the aircraft's cabin.
Southwest flight 3562 took off from Phoenix on Sunday night and was headed for Dallas Love Field Airport, according to KRQE-TV.
The plane was forced to land in Albuquerque after what might have been an electrical fire.
"The Captain declared an emergency to receive priority handling from air traffic controllers after deviating from the filed flight plan,” the airline told Fox News in a statement. “After safely landing, 140 passengers evacuated the aircraft on a clear taxiway. Initial reports indicate five Customers requested assessment by medical personnel."
The Albuquerque Fire Department tweeted that two people were taken to local hospitals. The extent of their injuries was not immediately known.
Several emergency vehicles could be seen on the runway after the plane landed.
Passengers were later placed on another flight to their original destination.
A Dallas Police officer aboard the flight tweeted that Dallas-based Southwest's flight attendants "did a great job!"
The Associated Press contributed to this report