WASHINGTON - Two suspects who may have been carrying bombs were shot dead Sunday, and a police officer was wounded, outside a Prophet Mohammed cartoon contest in Texas, organizers said.
The American Freedom Defence Initiative organised the event featuring far-right populist Dutch politician Geert Wilders, who has been outspoken against Muslims.
".garlandshooting cop shot - two suspects dead, awaiting bomb squad for possible explosives at our free speech event .sharia," political activist and AFDI co-founder Pamela Geller wrote on Twitter.
Wilders also commented on the incident, saying: "Shots fired at Garland Mohammed cartoon free speech event. I just left the building after speeching. .garlandshooting."
SWAT officials told ABC television news affiliate WFAA that the two male suspects drove up and opened fire on the Curtis Culwell Center in Garland, near Dallas, which was hosting the exhibit and cartoon contest billed as a "free speech" event.
The police officer was shot in the leg and was rushed to hospital, where he was expected to recover, according to local CBS news affiliate DFW.
Police were searching the area for a vehicle containing explosives.
A local police-themed blog that posts information coming from public scanner radio said a suspect had been spotted at a nearby store with a hand grenade, and that the expo centre and surrounding businesses were evacuated.
"There are multiple reports that two explosives have been placed in the area of Curtis Caldwell Center," the Rowlett/Sachse Scanner wrote on its Facebook page.
AFDI offered a $10,000 (S$13,300) prize for the winner of the cartoon contest.
Geller called the shootings "war on free speech."
"What are we going to do? Are we going to surrender to these monsters?" she wrote on her website.
"The war is here."
Caricatures of the Prophet Mohammed have triggered violent protests, including when the Danish daily Jyllands-Posten published 12 satirical cartoons in 2005, triggering deadly protests in some Muslim countries.
The cartoons were also published in French satirical weekly Charlie Hebdo, where gunmen killed 12 people in January.