(Photo: AP)

CHICAGO, Nov. 18 (Xinhua) -- A smoking bag in a stationary Southwest Airlines flight forced passengers to deplane at Chicago Midway International Airport on Monday.

Local media quoted Southwest as saying that Flight 285 to Austin, Texas, was in the process of boarding when a passenger's backpack, which contained electronics, started smoking.

Flight attendants put the backpack in a fire-resistant bag and moved it to the jetway, where Chicago police's bomb squad and arson unit quickly responded and put out the smoke.

No injuries were reported in relation to the suspicious bag.

Chicago Fire Department spokesman Larry Langford said that the passenger carrying the backpack heard a pop and then saw smoke coming from his backpack. The seat the bag was sitting on did not ignite.

At the time of the incident, only about 12 rows had been boarded. They were asked to leave the plane, Langford said.

"The flight will continue using a different aircraft and we thank our customers for their patience as we place nothing higher in importance than ultimate safety," according to the airline in a statement.