In 2007, a group of gun-wielding youths held up spectators in three cars leaving the circuit, and in 2006 members of the Toyota team were attacked by armed youths as they left the track. No one was hurt.
Button said he believed Saturday’s attack was random.
“It happens every year, but it’s the first time that it has happened to a driver,” he said. “It’s not a very nice feeling having to come to work in a bulletproof car with a policeman as the driver and two police cars, one in front and one in back, but that’s the way it is.”
Formula One boss Bernie Ecclestone downplayed the attack and said it could have happened anywhere.
“I’ve been coming here for 40-odd years, walking about, and I’ve never, ever had a problem,” Ecclestone told the Press Association. “That’s not just for the race, but at other times when I’ve been here too. I’ve also never been around where I’ve seen anybody have a problem.”
Veteran Brazilian driver Rubens Barrichello said on his Twitter page that it was “a shame” that the incident happened.
Button finished fifth in Sunday’s race after starting 11th on the grid. The result eliminated him from the drivers’ championship. Sebastian Vettel of Red Bull was first at Interlagos, followed by teammate Mark Webber and Ferrari’s Fernando Alonso.
The last race is next weekend in Abu Dhabi.
Associated Press writers Stan Lehman in Sao Paulo and Stephen Wilson in London contributed to this report.