Lewis Hamilton's Mercedes team robbed and held at gunpoint on eve of Brazilian Grand Prix

Lewis Hamilton has confirmed that members of his world-championship winning Mercedes team were robbed at gunpoint on the eve of the Brazilian Grand Prix.

A minibus, transporting Mercedes staff back to their team hotel from the Interlagos circuit, was held up at 10pm local time. One of the team had a gun held to their head, Hamilton said.

"One minibus was robbed at gunpoint," Mercedes 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."

Mechanics and other staff travel to and from the track by minibus and are advised against wearing branded team clothing away from the circuit.

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 Sunday's race - 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 a 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 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.

Mercedes have won both of this year's championships for the fourth year in a row with Hamilton arriving in Brazil as a four-time world champion.

Sunday's race is the penultimate round of the season.