McLaren and Pirelli have decided to cancel a tyre test at Interlagos due to security concerns following incidents at the Brazilian Grand Prix last week.
A Mercedes minibus was robbed at gunpoint on Friday, and, despite heightened security, a vehicle used by Pirelli was also targeted on Sunday.
As a result, McLaren and the tyre manufacturers have opted to call off their planned activities in Sao Paulo this week.
"We have jointly decided with Pirelli to cancel this week's tyre test at Interlagos," a McLaren statement posted on Twitter read.
"The safety of our people has always been our top priority, and, given recent events, we felt that it was an unnecessary risk to proceed."
A Pirelli release added: "Following a robbery attempt, neutralised by Pirelli security, on a Pirelli van at the Interlagos circuit last Sunday – after a weekend where similar episodes occurred with other teams – it has been decided to cancel the tyre test planned on Tuesday 14 and Wednesday 15 on the Brazilian circuit with McLaren.
"The decision, shared with McLaren, FIA and Formula 1, was made in the interest of the safety of the personnel, both McLaren's and our own, who would have participated in the test."