He said "gun shots were fired" and a weapon was held to the head of one team member.
"One minibus was robbed at gunpoint", a Mercedes spokesperson said. In a statement, Mercedes said, "Valuables were stolen but everybody is safe and uninjured which is the main thing".
In 2010, Jenson Button was subject to a similar incident while, in 2012, Formula 1 made sure that the race went on in the middle of a drug war in Sao Paulo.More news: The gender pay gap is largely a myth
Valtteri Bottas secured the third pole position of his career on Saturday after his Mercedes team-mate Lewis Hamilton had crashed in the opening minutes of an incident-filled qualifying session for Sunday's Brazilian Grand Prix.
Hamilton, who won his fourth Formula One championship two week ago in Mexico, walked away from the vehicle without appearing injured and will start at the back of the grid on Sunday.
Past year in Mexico, a team member, travelling in a chauffeur-driven vehicle from Mexico City Airport to the Mercedes' hotel, was targeted by two gunmen.
In 2016, ahead of the Mexican Grand Prix, a chauffeur-driven vehicle was looted by a gunman as a team member was being transported to the hotel from the Mexico airport.
Button described his driver as a "legend" after he managed to get the Briton to safety by fleeing through traffic. Looking behind there were two guys with a handgun and one guy with what looked like a machine gun. They were also unhurt.