Three were killed and dozens injured on Saturday at a F1-themed event coinciding with the Austrian grand prix.
In Graz, an hour’s drive from the Red Bull Ring, a car ploughed at high speed into a huge crowd of formula one fans, killing three people including a toddler and injuring at least 34, ten seriously.
"Next to something like this, our little world of formula one pales into insignificance," said Mercedes team boss and Austrian Toto Wolff.
The Austrian grand prix itself is promoted by Red Bull, where at the Red Bull Ring official Dr Helmut Marko told Kleine Zeitung newspaper: "This casts a shadow over the whole of Austria, but is has nothing to do with formula one."
It is believed the deliberate incident was perpetrated by a person with psychiatric problems.
"It is believed that this sort of thing happens only in America," said the security chief at the Red Bull Ring, "but unfortunately it can happen anywhere."
At the Red Bull Ring on Sunday, however, the show will go on.
"At this stage, no programme changes to the Austrian GP are planned," a spokesperson confirmed. "Our thoughts are now with the families and friends of the victims."