India, Oct. 5 -- A British Airways flight from London to Chicago declared an emergency over Ireland on Sunday and began diverting back to London, according to flight-tracking data.

British Airways flight BA295 was seen squawking 7700, the internationally recognised transponder code indicating a general emergency.

The exact reason for the emergency has not been made public so far.

What does Squawk 7700 mean?

The four-digit 7700 transponder code is used by pilots to alert air traffic controllers that an aircraft is experiencing a general emergency and may require immediate assistance.

The aircraft's descent to below 10,000 feet could be consistent with a controlled rapid descent, a procedure commonly used following a suspected cabin de...