Marksman practices at a range in Washington.
Marksman practices at a range in Washington.

Gun sales in Maryland, USA, have soared ahead of a new law designed to prevent the mentally ill from obtaining firearms and restricting the sale of automatic firearms.

The law, to be introduced next week, means that anyone buying a handgun in the state must be fingerprinted, as in Connecticut, Hawaii, Massachusetts, New Jersey and New York, which have already enacted similar legislation.

It also forbids those who have been committed to a mental health facility to buy or own a gun.

Around 45 types of assault weapon will also be banned, though those who already possess the guns will be allowed to keep them.

''States with similar licensing provisions have substantially lower gun death rates than states that do not. So, if we want better results, we have to make better choices, and this legislation is part of that series of better choices,'' said Governor Martin O'Malley.

A surge in sales of the weapons has been reported ahead of Tuesday, when the law comes into effect.

Maryland State Police have received 106,772 gun purchase applications so far this year, compared with 70,099 applications last year - the previous annual record.

"There's never been this kind of increase," state police spokesman Greg Shipley told the AP. He said people have been applying for guns at the rate of about 1,000 per day over the past two weeks.

Vincent DeMarco, president of the Marylanders to Prevent Gun Violence campaign group, hailed the new law, and called for other states to enact similar legislation.

"We are enacting the most effective tool a state can enact to reduce gun violence, and we encourage the rest of the country to do the same - for their sake and ours," he said.

However, opponents say the law contravenes their second amendment right to bear arms, and claim that criminals will find a way to acquire firearms regardless.

"They are going to continue to buy them on the street," she said. "They are going to continue to break into people's homes and steal them. They will get them," said Senator Nancy Jacobs, a Republican who opposed the legislation.

Gun activists are to challenge the legislation in the courts, arguing that it is unconstitutional.