A group of robbers tried to blow the safe of the Vilamoura Casino on January 12.
According to GNR police, the robbers were clients at the Black Jack disco inside the casino until about 6 am.
When the disco closed and two GNR policeman who were on duty had left, the group put their plan into action.
Using a torch and a bottle of acetylene, they started work on the safe door but the heat released by the torch triggered the smoke sensors.
A night watchman who went to see what was happening was held the robbers.
However, a radio transmitter that he was carrying alerted the director of the casino, who immediately contacted the GNR police. By the time officers arrived at the scene, the burglars had fled the scene.
Police investigations are continuing.