Texas police shot dead two gunmen who opened fire yesterday outside an exhibit of caricatures of the Prophet Muhammad that was organised by an anti-Islamic group and billed as a free-speech event.

The shooting in a Dallas suburb was an echo of past attacks or threats in other Western countries against art depicting the Prophet Muhammad. In January, gunmen killed 12 people in the Paris offices of French satirical magazine Charlie Hebdo in revenge for its cartoons.

The attack took place at about 7pm in a parking lot of the Curtis Culwell Centre, an indoor arena in Garland, northeast of Dallas. Geert Wilders, a polarizing Dutch politician and anti-Islamic campaigner who is on an al-Qaeda hit list, was among the speakers at the event.

Police said they had not determined the identity of the two gunmen or whether they were linked to critics of the event who had branded it anti-Islamic.

As a precaution, a police bomb squad was checking the suspects’ car, and the immediate vicinity of the Culwell Centre was evacuated, city police spokesman Joe Harn said. Investigators were keeping their distance from the bodies of the gunmen, which were close to the car, until the vehicle was deemed clear of explosives, he said later.

Shortly before midnight police alerted media that a strong electronic pulse would be activated near the scene, presumably as part of the bomb squad’s work, and a loud boom was heard moments later, though police did not comment further on what was done.

The exhibit was organised by Pamela Geller, president of the American Freedom Defense Initiative (AFDI). Her organization, which is described by the Southern Poverty Law Centre as a hate group, has sponsored anti-Islamic advertising campaigns in transit systems across the country.

A police officer prevents attendees from leaving the Muhammad Art Exhibit and Contest after shots were fired outside the venue in Garland, Texas, yesterday. Photos: Reuters

Organisers of the “Muhammad Art Exhibit and Contest” said the event was to promote freedom of expression. They offered a $10,000 prize for the best artwork or cartoon depicting the Prophet, as well as a $2,500 “People’s Choice Award.”

Suspects opened fire with automatic rifles at an unarmed security officer

Depictions of the Prophet Muhammad are viewed as offensive in Islam, and Western art that portrays the Prophet has sometimes angered Muslims and provoked threats and attacks from radicals.

In the incident, the two suspects drove up to the building as the event was ending, and opened fire with automatic rifles at an unarmed security officer, striking him in the leg, police and city officials said Garland police officers who were assisting with security returned fire, killing both suspects, Harn said.

One of the suspects, after being initially wounded by police gunfire, was seen reaching for a backpack and was shot again and killed, Garland Mayor Douglas Athas later told CNN.

The security officer was treated at a local hospital and later released, Harn said. No one else was injured.

Most of the 200 people attending the event were still inside the arena when the violence unfolded and were unaware of what had happened until police came into the building and told everyone to stay inside because of a shooting.

The mayor said the city had permitted the event even though officials knew its inflammatory theme could provoke an attack.

“There was concern, which is why we had heightened security in the area, but we all swear to uphold the Constitution: free speech, free assembly and in this case perhaps, free religion,” Athas said. He said the school district that owns the building had posted extra security officers at the venue, and the city of Garland also had a number of security and SWAT (special weapons and tactics) teams in the area.