California gun owners - sparked by outrage over a schoolyard mass killing - are defying a state law requiring them to register an estimated 300,000 military-style semi-automatic weapons, state officials said Thursday.

With only four days left of a one-year registration period, fewer than 7,000 of the weapons have been registered, Robert Drake, of the state Department of Justice, said."What's happening here is civil disobedience by some people," he said.

The 1989 law, the first of its kind in the United States, was passed after a deranged drifter, Patrick Purdy, fired 105 rounds from a Chinese-made AK 47 semi-automatic assault rifle in two minutes into a schoolyard at Stockton, Calif. Five children were killed and 30 others injured before Purdy killed himself with a handgun.

The California law was followed by a national law banning the import of five makes of semi-automatic rifles, including the Israeli-made Uzi, a favorite among drug dealers.