STOCKHOLM: The Swedish artist who faced numerous death threats after depicting Prophet Muhammad as a dog has been pelted with eggs by an a group of people during a university lecture on the limits of the freedom of expression.

According to a police statement, Lars Vilks was unharmed in the attack that occurred at Karlstad University in southwestern Sweden late Tuesday evening.

No one has yet been arrested for the assault, but police say they are investigating the incident.

The 65-year old artist has faced a string of threats over his 2007 sketch, which rekindled a debate over free speech and Islam that had raged a year earlier after a Danish newspaper printed 12 cartoons of Muhammad. Images of the prophet, even favorable ones, are considered blasphemous by many Muslims.