The gun group's 128th annual convention was held in Denver, close to the scene of the killings, despite requests from the city's mayor, Wellington Webb, to cancel it.

Thousands of opponents circled the convention hotel, some carrying signs that read "Shame on the NRA" and "NRA, Pusher of Child Killer Machines".

Paul Reynolds reports on the NRA's defence

Students from Columbine High School, where 12 students, a teacher and the two gunmen died, were among the protesters.

The NRA cut the meeting from three days to one and eliminated a gun exhibit.

Tom Mauser, demonstrating for his son

The NRA meeting drew a far larger crowd than expected, with older men in fishing caps mingling with younger men in suits and ties. Loudspeakers let the overflow crowd to hear the speeches in the hotel lobby.

The movie star told about 2,500 cheering supporters that gun owners were being unfairly blamed. "We will not be silent or be told, 'Do not come here, you are not welcome in your own land'," he said.

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Mr Heston added: "We cannot, we must not let tragedy lay waste to the most rare, hard-won right in history," referring to the Second Amendment's right to bear arms.

He accused the Clinton administration and the media of using the Columbine killings to push an agenda.

Charlton Heston: "We will not be silent"

Among the estimated 8,000 demonstrators gathered outside the annual meeting was Tom Mauser, father of Columbine victim Daniel Mauser, who carried a photo of his son that said, "Don't let my son's death be in vain."

"I am here today because my son would want me to be here. If my son was alive, he would be here, too," Mauser said.

In the run up to the convention President Clinton urged Mr Heston to relax opposition to gun controls. In a reference to Mr Heston's 1960s film role as Moses, he said the actor should lead his people into a promised land of the NRA being used for good.