Kimi Raikkonen finished the Belgian GP ninth after a series of collisions with Max Verstappen

Max Verstappen will cause a "massive accident sooner or later" if he does not change his driving tactics, Ferrari driver Kimi Raikkonen says.

Raikkonen was angry after an incident during Sunday's Belgian Grand Prix, the latest of a series of controversies related to the Dutchman's driving.

The Finn said: "If I had not braked, we would have had a massive accident.

"It will happen sooner or later if this doesn't change. I am fine with good, hard racing but that is not correct."

Raikkonen swore over the radio because of a tactic Red Bull's Verstappen has adopted repeatedly this year, which is to drive in the middle of the track and only make a defensive move at the last moment when he sees which way the driver attacking is coming.

Verstappen, Raikkonen and Ferrari's Sebastian Vettel collided at the first corner of the race, with all three cars suffering damage, but it was an incident on the Kemmel straight later in the race that angered the Finn.

"Other guys defend but they do it correctly," Raikkonen said. "He waits and waits and turns after me and I have to brake and slow down. It is not exactly what should happen.

"Maybe it needs an accident before it makes it more clear to everybody but hopefully not because it can be bad for someone. Nobody wants to see anybody get hurt.

"Something is not correct in my view, but the stewards have a different opinion."

Raikkonen became sandwiched between Verstappen and Vettel, which led to their first-corner accident

Verstappen rejected suggestions he needed to rethink his tactics.

"To be honest, it's a big lie," the 18-year-old said. "I'm just defending my position and if somebody doesn't like it, it's his own problem."

He added that Raikkonen and Vettel should be "ashamed" of criticising him and accused them of causing the first-corner collision between the three that damaged all their cars.

"If they screw up my race, I'm not going to make it easy for them," he said. "I think they should understand that.

"I'm not going to say: 'come on through'. But all that happened after turn one. If turn one hadn't happened, I wouldn't have been so aggressive and pushed Raikkonen out like that."

Verstappen's team boss Christian Horner said: "It was firm, it was on the edge. He got away with it. I'm sure he'll have a good look at it and maybe learn a bit for future races."

Mercedes F1 boss Toto Wolff said Verstappen's driving was "refreshing but it's dangerous".

"He comes in here no fear, no respect, puts the elbows out," Wolff said.

"He reminds me of the great ones, of Lewis [Hamilton], of Ayrton Senna and you can clearly see some guys around are starting to think twice how to overtake him.

"Until now, all that has proven he is on the right track. The FIA has not penalised him. The only thing that has happened is that he was being given a hard time in some driver briefing.

"Maybe he is going to get a harder time in the next driver briefing. I just fear it might end up in the wall heavily one day."

Mercedes F1 boss Toto Wolff said Verstappen reminded him of greats such as Ayrton Senna

Raikkonen's team-mate Sebastian Vettel, who had his own on-the-edge tussle with Verstappen during the race, said he would try to "educate" the Red Bull driver.

"I am not a fan of penalising people," the four-time world champion said. "We need talk to each other and have respect.

"There have been a couple of manoeuvres that the rest of the field is not happy with his behaviour.

"The best way to educate is just to talk rather than create a fuss in the media. We are men."