McLaren's scheduled tyre test with Pirelli at Interlagos this week has been cancelled due to ongoing security concerns linked with the Brazilian track.
Stoofel Vandoorne and Lando Norris were due to stay on after yesterday's Brazilian GP to test Pirelli's 2018 compounds.
But another robbery attempt Sunday evening against Pirelli staff has roiled the manufacturer's personnel.
Luckily the attempt was neutralized by Pirelli's security, but the latest incident comes after a series of attacks or robbery attempts on members from Mercedes, which were held at gunpoint and robbed on Friday, Sauber and Williams.
"We have jointly decided with Pirelli to cancel this week’s tyre test at Interlagos," McLaren said on its Twitter account.
"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."