The six were arrested on Saturday after trying to open the emergency exit of an aircraft that was in movement on the Humberto Delgado airport’s tarmac.
The group had earlier arrived in the Portuguese capital on a flight from Casablanca (Morocco) to Algiers (Algeria) via Lisbon.
They were detained by PSP officers inside the aircraft, after attempting to open an emergency exit to flee the plane while in Europe.
The flight from Morocco had landed at around 8am on Saturday morning with the passengers deplaning to transit for the outbound leg to Algiers.
While in transit at Lisbon airport, three of the passengers attempted to evade security measures, but were put back in line by airport authorities.
Later, on the aircraft, a group of six Algerians including the three who had tried to flee the airport, attempted to open the plane’s emergency exit door while the aircraft was moving.
Following the incident, the Algeria-bound flight, which was due to depart at 3.30pm, had to be completely evacuated of all passengers and only resumed its journey later that evening at around 7pm.
A joint statement from the PSP police and SEF immigration officials said the six men were arrested as part of combined efforts to oversee movements deemed to be ‘of risk’.
On Monday the six were brought before a judge and cleared of jeopardising air travel safety.
They will remain, however, under the observation of SEF immigration officials at a temporary housing centre until deported on counts of illegal immigration.
In a related event, earlier this year, in July, four Algerians who broke through Lisbon airport security barriers were handed suspended jail sentences.
The four Algerian nationals had invaded Lisbon’s airport runway on 30 July and were handed four-year suspended prison sentences by a Portuguese judge for jeopardising air transport safety.
The foursome were charged with entering a space closed to the public, jeopardising air transport safety, and one of them was also charged with violation of a banning measure as he was not allowed to enter Spain, which also stopped him from entering any other Schengen space country.
The defendant who was charged with the last count was absolved as it was not proven that he knew the Spanish decision also covered Schengen countries.