Two gunmen were shot dead by police in the US outside what was said to be a contest on cartoons about the last prophet of Islam Muhammad (PBUH).
Police alleged that the men who were armed started shooting at a security man which forced them to retaliate and kill the two in the city of Garland in Texas.
The contest is said to have been organised by the American Freedom Defense Initiative (AFDI) offering a $10,000 prize for the winner.
The organisation is run by controversial blogger and activist Pamela Geller and is listed as an anti-Muslim group by the Southern Poverty Law Center, a civil rights group.
The group’s website said more than 350 cartoons were submitted for the event that would “stand for free speech and show that Americans will not be cowed by violent Islamist intimidation.”
Dutch politician Geert Wilders, a critic of Islam who said last week the U.S. should ban Muslim immigrants, was the event’s keynote speaker. He mentioned on Twitter the shots being fired and said he left the building after his address.
Many Muslims find depictions of Prophet Muhammad to be insulting to Islam. The issue has sparked tensions with those who see the drawings as an issue of free speech.
In January, two Islamist radicals attacked the French satirical magazine Charlie Hebdo, which had featured multiple cartoons depicting the prophet. Last week, Charlie Hebdo cartoonist Renald Luzier said he would no longer draw the prophet, saying the subject no longer interests him.
About 200 people had been attending the Muhammad Art Exhibit when they were told of a shooting outside.
Local police said they have not yet been able to identify the gunmen.
