US police say they have shot dead two gunmen who had opened fire outside an event in Texas featuring a contest to draw cartoons of the Prophet Mohammad.<br /><br /> According to the authorities, the men drove up to the Curtis Culwell Center in the city of Garland near Dallas and began shooting at a security officer.<br /><br /> Police returned fire, killing the men.<br /><br /> The security officer who the authorities say was hit in the leg was treated in hospital and released. No-one else was injured.<br /><br /> Police said they did not know who the gunmen were or whether they were linked to the event’s critics who had branded it un-Islamic.<br /><br /> Their bodies remained by their car for some time while the vehicle was checked for explosives.<br /><br /> “We started evacuating businesses nearby because our concern became the vehicle that they’d come in and possible any bombs that may be in that vehicle,” said Garland Police spokesman Joe Harn.<br /><br /> Among the speakers at the event, billed as the “Muhammad Art Exhibit and Contest”, was the far
