Truck crash that killed cartoonist who drew Muhammad may be due to a blown-out tire on his bulletproof car, police say

• Lars Vilks died Sunday when a car driven by his police minders crashed into a truck in Sweden.
• Police say a tire on the vehicle may have blown out, although it was supposed to be puncture-proof.
• Vilks was given protection in 2007 after getting death threats for insulting the Prophet Muhammad.

Police investigating the crash that killed the Swedish artist famous for drawing the Prophet Muhammad as a dog say a blown-out tire may be to blame.

Larks Vilks, 75, was killed at 3:30 p.m. on Sunday when his police escort vehicle collided head-on with a truck near Markaryd, southern Sweden. His two police chaperones also died.

Vilks had lived under police protection since 2007 after threats were made against his life following the publication of his incendiary cartoon.

In the Islamic faith, depictions of Muhammad are considered offensive, and cartoons showing him have prompted violent backlashes before.

Swedish police are still investigating the cause of the crash, and said Sunday they have no evidence suggesting the collision was intentional.

Stefan Sintéus, the head of the police investigations unit in southern Sweden, said Monday that the crash may have been caused by a tire blowing out on the police car, even though they were supposed to be puncture-proof, SVT News reported.

"If there was some kind of blowout, that something we need to look at and that's what the forensic analysis should show," he said.

The car carrying Vilks collided with the truck after crashing through the fence running down the middle of the motorway, he said.

"A bulletproof vehicle weighs about 4.5 tonnes and can build up a lot of momentum. That should be able to explain how it could drive through the wire railing," Sintéus said.

The police car was travelling at high speed shortly before the crash, Sweden's Expressen newspaper reported, and caught fire after impact.

Vilks has lived a fairly public life in Sweden since he was thrust into the spotlight in 2007, often appearing at events to defend free speech.

At the time of his cartoon, Al Qaeda put a $100,000 bounty on Vilks' head and his house was fire-bombed.

But he also had a number of near misses.

• In 2010, police deployed tear gas after a group of protesters attacked Vilks as he gave a lecture at Uppsala University.
• In 2015, one person was shot dead at a free-speech event hosted by Vilks at a cafe in Copenhagen, Denmark.
• In 2011, Vilks was also the target an attempted terror attack at the Gothenburg Book Fair.