One of the two citizens was detained for trying to travel to the UK on a forged Italian ID card that had been stolen.
A statement from SEF explained: “The 21-year-old individual who wanted to travel to Birmingham was told to check in with the Department of Investigation and Penal Action (DIAP) in Faro” and will await further measures in freedom.
Meanwhile, a second individual attempted to enter the country using a passport from Guinea-Bissau with information that had been altered.
The 21-year-old who had arrived from London is a legal resident in Portugal but was also taken to the DIAP in Faro, SEF said.