LONDON (Reuters) – Pirelli and McLaren have canceled a Formula One tire test scheduled for the Brazilian Grand Prix circuit on Tuesday and Wednesday after teams were targeted by armed robbers in Sao Paulo over the weekend.

“Following a robbery attempt, neutralized by Pirelli security, on a Pirelli van at the Interlagos circuit last Sunday…it has been decided to cancel the tire test,” Pirelli said in a statement.

“The decision, shared with McLaren, FIA and Formula One, was made in the interest of the safety of the personnel, both McLaren’s and our own, who would have participated in the test,” it added.

Sunday’s attack came after armed robbers held up members of Lewis Hamilton’s Mercedes team as they left the circuit in a minivan on Friday night.

Four-times world champion Hamilton, who was not present, said shots were fired and one team member had a gun held to his head.

Williams and Sauber team members reported other incidents outside the circuit while a car used by officials from the sport’s governing body, the FIA, was also targeted.