Door alert forces plane back

[File photo] A Singapore Airlines Airbus A380, not Flight SQ 866, approaches Singapore International Airport on January 7, 2014.

• A cockpit warning about a cargo door went off mid-flight on an Airbus A380


• The superjumbo, headed for Hong Kong, turned back to Singapore, the airline says


• It landed safely and passengers were transferred to a replacement plane

(CNN) -- A Singapore Airlines flight to Hong Kong had to turn back in mid-flight Friday after the pilots received an alert about a problem with a cargo door on the plane, the company said.

The aircraft, an Airbus A380 superjumbo, returned to Singapore's Changi airport on Friday afternoon "as a result of a cockpit warning relating to a cargo door," the airline said in an e-mailed statement.

Flight SQ 866 landed safely back at Changi at 2:20 p.m. local time, Singapore Airlines said, adding that passengers would be transferred to a replacement flight to Hong Kong.

The airline didn't provide further details about the incident, nor did it immediately respond to a question from CNN about whether the cargo door issue affected cabin pressure.

The replacement aircraft was expected to arrive in Hong Kong at 8:40 p.m., more than three and a half hours after the original scheduled arrival time, according to the Singapore Airlines website.

The double-decker A380 is capable of carrying more passengers than any other commercial aircraft.

CNN's Euan McKirdy contributed to this report.