Members of Lewis Hamilton's world-championship winning Mercedes team were robbed at gunpoint as they left the Interlagos circuit on Friday night.
A minibus, transporting Mercedes staff back to their team hotel, was held up at 2200 local time. One of the team had a gun held to their head, Hamilton said.
"One minibus was robbed at gunpoint," a Mercedes spokesperson said. "Valuables were stolen but everybody is safe and uninjured which is the main thing."
Jenson Button was ambushed by gunmen when he left the same track back in 2010.
Hamilton tweeted on Saturday morning: "Some of my team were held up at gunpoint last night leaving the circuit here in Brazil. Gun shots fired, gun held at ones head.
"This is so upsetting to hear. Please say a prayer for my guys who are here as professionals today even if shaken."
Staff from the British-based Williams' team had a narrow escape after a van was held up in front of their minibus as they left the circuit. The team confirmed it had witnessed a van being targeted at gun point ahead of them, but they were able to get away. Meanwhile personnel from the FIA, the sport's governing body, were also caught up in a separate incident, but escaped unharmed.
Hamilton added: "This happens every single year here. F1 and the teams need to do more, there's no excuse!"
The harrowing incidents - which are likely to raise security concerns ahead of the penultimate round of the season here in Brazil - mark the second time in a little more than 12 months a Mercedes' staff member has been robbed at gun point.
Last 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. The member of the Mercedes team and driver were unhurt in the ordeal.
Button was threatened by gunmen in Sao Paulo ahead of the 2010 Brazilian Grand Prix. Button, then the reigning world champion, was returning to his hotel following qualifying at the Interlagos circuit when his vehicle was approached by at least three men brandishing machine guns.
Button, who was travelling with his late father John, trainer Mike Collier and manager Richard Goddard, managed to flee the scene unharmed in the incident.
Three Sauber engineers were robbed at gunpoint on the same evening. They were also unhurt.