Spanish police were still searching for 12 passengers who fled their plane Wednesday after an emergency landing at Barcelona airport following what may have been a fake medical incident, officials said.

They were part of a group of 28 people on a Pegasus Airlines flight from Casablanca to Istanbul after it made a pre-dawn landing at Barcelona's El Prat airport.

Police were originally searching for 14 passengers, but later announced that they had made two arrests.

It is the second such incident in just over a year.

At 4:30 am (0330 GMT) the plane requested an emergency landing because "a female passenger's waters had supposedly broken", said a source in the central government's delegation in Catalonia.

The plane was met by an ambulance and three police patrols but "as they were disembarking the pregnant woman, a group of 28 people left the plane and tried to flee", the source said.

Police managed to detain 14 of them, including the pregnant woman, but five were returned to the plane at their own request after being accepted back by the airline staff.

"The woman was taken to Sant Joan de Deu hospital for a check-up, which found no signs she was in labour so she was discharged and arrested for disturbing the public order by claiming she had gone into labour," the source said.

The authorities were meanwhile processing the other would-be migrants to ensure their return to Morocco.

The previous incident was on November 5, 2021, involving a flight from Morocco to Turkey.

Another plane flying from Casablanca to Istanbul was forced to make an emergency landing in Mallorca after one of the passengers appeared to be unwell.

After the passenger was disembarked from the plane with a companion, another 21 people fled.

The passenger, who had appeared to be going into a diabetic coma, was taken to hospital but found to be fine. He was then arrested, while the companion fled.

Police arrested 12 people, including a passenger who created a disturbance on the plane, while another 12 managed to flee, prompting a manhunt.

All but one were thought to be Moroccans.