ANNAPOLIS, FEB. 14 -- Gun owners packed a legislative hearing today on Gov. William Donald Schaefer's plan to ban assault weapons in Maryland, holding signs that called him a fascist and deeming his proposal part of a class war against rural conservatives.

Police, gun-control groups, teachers and the Maryland Chamber of Commerce retorted that while the number of assault weapons on the street may be small compared to handguns, outlawing them might avert a tragedy.

"At this time the numbers . . . are not great," said Col. Elmer H. Tippett, superintendent of the Maryland State Police. But, he added, "Put yourself in the position of a police officer when he walks into a darkened alley or into a fortified room or even to a car and is confronted with a weapon such as this."

"What you have to look at is the potential that the weapon can do," Tippett said in an earlier interview. "They are instruments for killing. You don't allow everybody to have a TOW missile to carry around."

Supported strongly by law enforcement leaders, the Schaefer legislation would make it illegal to sell 39 different guns, while owners of the esimated 30,000 assault weapons in Maryland would have to get permits to keep them. Passage of the bill is not guaranteed. Senate Judicial Proceedings Committee Chairman Walter M. Baker (D-Cecil) is particularly skeptical.

But Schaefer says he is committed to expanding gun control beyond the law that Marylanders ratified in 1988, banning cheap handguns known as Saturday night specials.

Focus shifted to the more expensive assault weapons after five California schoolchildren were killed in 1989 by a man armed with an AK-47, a military-style weapon that is among the 39 Schaefer wants banned. California and New Jersey quickly outlawed assault weapons after the slayings, while Maryland gun-control advocates, who sought a ban two years ago, compromised then on a seven-day waiting period for purchases of such weapons.

As gun-control groups again seek to ban assault weapons, there is controversy over whether such action would reduce crime.

In Maryland, the state police approved 971 assault weapon purchases in 1990 -- compared with more than 26,000 handgun sales. According to state crime reports, "long guns" -- primarily hunting rifles and shotguns -- were involved in only 10 percent of the 540 slayings in Maryland in 1989. Handguns accounted for more than half the killings. Police say assault-style guns are rarely seized as murder weapons in Maryland.

"The battle . . . is a class struggle between urban liberals who have very little knowledge of guns and therefore fear them, and rural conservatives, who understand guns, are comfortable with them and who do not use them to commit crimes," said Robert A. McMurray, head of the Maryland State Rifle and Pistol Association.

The federal Bureau of Alcohol, Tobacco and Firearms estimates that of the 200 million guns in this country, 3 million are assault weapons -- typically semiautomatic rifles and pistols patterned after fully automatic military designs. "Semiautomatic" means the weapon fires a bullet and loads another with each pull of the trigger.

Despite their notoriety, assault weapons are no more powerful than other rifles, shotguns and handguns and do not necessarily fire faster than semiautomatic hunting guns or pistols not covered by the proposed law.

But supporters of the ban argue that there are important distinctions: Police say features such as threads for a silencer and the "shoot-from-the-hip" design make the assault weapons more dangerous than firearms that turn up at Eastern Shore duck blinds. The ability to hold large-capacity magazines, typically 30 or more bullets, also make the weapons a special threat, police say.

According to Bureau of Alcohol, Tobacco and Firearms statistics, about 10 percent of the gun traces requested by local police now involve assault-style guns, even though the weapons represent only 2 to 3 percent of the guns on the street.

"My officers are simply not equipped to deal with drug dealers who use these types of weapons," said David B. Mitchell, the Prince George's County chief of police.

The Metropolitan Washington Council of Governments this week called for tougher gun controls, including a ban on some assault weapons. The Virginia legislature recently killed a proposal for a three-day waiting period for buying handguns. It is still considering expanded background checks for gun buyers.