NEW YORK (REUTERS) - Pro-gun activists held "high noon" rallies across the United States on Saturday to defend the right to own firearms that they say is being threatened by President Barack Obama's gun-control proposals.

The US debate over gun control erupted in mid-December after a man armed with an assault rifle killed 20 first-graders and six adults at an elementary school in Newtown, Connecticut - the deadliest of a string of US shooting sprees last year.

"We are law-abiding citizens, business owners, military, and we are not going to be responsible for other people's criminal actions," former Marine Damon Locke said to applause at a Florida rally he had helped organize.