Several residents in Portimão reported feeling the earthquake, with many people reported to have headed outdoors as the earth shook beneath them just after 7pm on Monday evening
One resident in Alvor told The Portugal News: "We have been living here for more than 20 years and while we have felt some earthquakes over the years, this was by far the strongest."
Another frightened resident in Praia da Rocha said: "My whole house jumped. It was like an explosion with no bang."
In a statement, the Portuguese Met Office said it was recorded 8 kilometres northwest of Portimão.
The earthquake is not believed to have caused any significant damage, but officials said further information would be available in the event of any occurrences resulting from the earthquake being made available.
We felt it at Vale de Pinta. Bottles rattled in the fridge!
By Carolyn Lee from Algarve on 11 Sep 2017, 19:57
We felt this in Vale da Telha
By Alan from Algarve on 11 Sep 2017, 21:19
Felt just outside queries too
By James from Algarve on 11 Sep 2017, 22:10
I was staying at the praia da Mar appartmento when at 7 o clock the whole appartment shook and the tv nearly fell from its stand ...it was fairly frightening as at the time we didn't know what had caused the shaking
By Mick mcavinue from Algarve on 12 Sep 2017, 01:39
This was one of those very few earthquakes I could feel during last 20 years! My house like jumped! I thought that it was a bang from Monchique stone place!
By Maria from Algarve on 12 Sep 2017, 05:48
Certainly felt in Fernando. Felt like a very heavy lorry passing by.
By Matthew from Other on 12 Sep 2017, 07:00