CHICAGO (CBS) — A flight from Chicago to Frankfurt, Germany, was diverted to Toronto late Monday when the pilot spilled coffee, accidentally setting off a hijacking alert.

United Flight 940 landed safely at Pearson International Airport late Monday, according to a Transport Canada report. The spill caused distress signals to go out, including code 7500, which means hijacking or unlawful interference.

LISTEN: Newsradio 780’s Pat Cassidy Reports

The Canadian defense department was notified and, with the help of United Airlines staff, the flight crew confirmed the alert was due to a communication problem and not a hijacking.

A report on Transport Canada’s website said the U.S. Federal Aviation Administration reported that United’s corporate office had indicated the pilot “had inadvertently squawked a 7500 code after spilling coffee on the aircraft’s radio equipment, which interfered with the communications equipment.”

“The flight crew had advised that they had communication problems and subsequently reported that they had some navigation problems as well, and from there the pilot in the command diverted the flight onto to Toronto,” Maryse Durette, a Transport Canada spokeswoman, said Wednesday.

United spokesman Rahsaan Johnson had said Tuesday that the pilot elected to divert the flight rather than cross the Atlantic Ocean while experiencing a communications problem. United did not immediately return a call Wednesday to comment on the reported coffee mishap.

The Boeing 777 was carrying 241 passengers and 14 crew members. Johnson said United flew them back to Chicago on another plane and put them up in hotel rooms overnight.

(TM and © Copyright 2010 CBS Radio Inc. and its relevant subsidiaries. CBS Radio and EYE Logo TM and Copyright 2010 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed. The Associated Press contributed to this report.)