Two men arrested on a Pakistan International Airlines plane at a London airport were questioned on Saturday after they were detained on suspicion of endangering an aircraft.
Flight PK709 from Lahore in Pakistan had been due to land at Manchester in northern England with 297 passengers on board, but was diverted to Stansted airport shortly before arrival.
The incident was not believed to be terror-related, according to AFP news agency. An airline source told the agency the incident had stemmed from a family row on board.
“There was a family of eight to 10 people on the plane and they were quarrelling among each other,” the PIA source said.
“When PIA staff approached them and asked them to calm down, they told them to go away otherwise they would blow up the plane.
“PIA staff became scared and they raised the alarm to avoid any untoward situation.”
Police said they were alerted 10 minutes before the plane was due to land in Manchester at 1:30pm (1230 GMT) on Friday.
They were told a threat had been made to the safety of an aircraft.
The arrested men were taken to a police station “where they will remain in custody pending interview by detectives”, the local Essex Police force said.
The remaining passengers disembarked under police escort and were taken to the terminal building for a debriefing.
“The plane will remain at its current location and will be subject to forensic examination by specialist officers,” the police said.
“At this point in time no suspicious items have been recovered.
“This incident is being treated as a criminal offence.”
Fighter jets were scrambled to escort flight PK709 into Stansted, London’s third-biggest airport, where it touched down at 2:15pm (1315 GMT).
A Ministry of Defense spokesman said that Typhoon fighter jets had been launched from a Royal Air Force base after the incident was signaled by the plane’s crew.
The airline said a “technical fault” was responsible but declined to comment on speculation that the plane’s engine had failed.
“We have begun a full investigation into the incident,” a British Airways spokesman said.
The London Ambulance said it had treated three people for minor injuries.
David Gallagher, a passenger on the flight, said “big flames” had been visible from within the cabin.
“About eight or nine minutes into the flight there was a loud popping sound, not an explosion but definitely not usual sounds,” he told BBC television.
“There was some concern from passengers -- people gasping and louder exclamations.
“The captain came on very calmly, said he was aware of the situation and that everything was running normally and he was going to run some tests to see what the right course would be.
“Then another five minutes after that there was a loud sound, and this time the right engine was clearly on fire.”
He praised the cabin crew as “outstanding and completely calm, reassuring and professional during the whole incident.”