Police and Jittery Public Respond to Threats and Fear : Bomb scares: Officers say a marked increase in incidents is caused by people more likely to report their suspicions and by a jump in fake claims.

Pierce College was evacuated Friday morning after a man called to say that he had planted a bomb on campus.

Three hours later, the telephone rang at Piute Intermediate School in Lancaster. The message was similar, and teachers rushed 1,000 students out of classes.

Both threats--which turned out to be false alarms--are examples of what police say is a dramatic increase in bomb scares in the San Fernando Valley and surrounding areas since the start of the Persian Gulf War.

“The first week of this war our unit has been run ragged,” said Detective Don Tabak of the Los Angeles Police Department’s criminal conspiracy unit, which investigates bomb-related incidents in the Valley.

So far, no explosive devices have been found.

Law enforcement officials have yet to compile comprehensive statistics on recent bomb-related calls, either in the Valley or citywide. The Van Nuys station has been receiving as many as two a day, Lt. Warren Knowles said. The sheriff’s Antelope Valley station, which averaged three calls a month last year, has responded to 11 in the last eight weeks.

The reason for the increase appears to be twofold: People are worried about Iraqi President Saddam Hussein’s threats of terrorist attacks and are more apt to report suspicious circumstances, and such widespread worry often inspires false telephone threats.

“Some morons know that all the local agencies are reacting to bomb threats,” Tabak said. “They get off on seeing the police cars come out and surround a bank or a grocery store.”

Nowhere was the concern over possible terrorism more apparent than at Pierce. Bomb threats during final exams are not entirely unusual there, but the call to evacuate was. College President Dan Means said the war influenced his decision to evacuate.

“With the situation the way it is, we can’t afford to take any chances,” Means said.

While many of the recent bomb scares have begun with telephone threats, others have come from calls by people reporting suspicious-looking packages:

* Outside the Van Nuys Courthouse last week, a man left his briefcase beside a hot dog stand. Police cordoned off the street until the owner returned to retrieve his forgotten possession.

* At a Northrop plant in Palmdale, employees in the shipping department received a parcel they thought looked suspicious. The sheriff’s bomb squad exploded the package, only to find that it contained a harmless electrical part.

* At a Van Nuys apartment complex, residents mistook a child’s toy for a bomb.

“Paranoia is running at its highest right now,” Tabak said. “People see normal everyday trash, a paper bag in the gutter, and they call the police.”

Said Chet Spencer, a commander of the Los Angeles Police Department’s Valley Bureau: “Everybody’s concerned about terrorism. People see something and that’s how they react. You can’t fault them.”

Bomb scares have occurred at a variety of public places, police said.

The Sherman Oaks Galleria received two telephone threats last weekend. Jan Marlyn of Sherman Oaks was watching a movie in the mall’s cinema Jan. 18 when police walked in.

“They told us to get up and leave quietly. They emptied the whole mall,” Marlyn said. “I thought it’s a bomb scare, it’s a terrorist act. I was very scared.”

As part of standard procedure, police officers or sheriff’s deputies respond in a patrol car to each bomb-related call. At schools and businesses, any decision to evacuate is left to administrators. Officers will help search for suspicious-looking packages.

If an unusual package is found, the bomb squad is called out.

Police continue to encourage the public to be cautious and report suspicious packages. But at least one detective said there is a line between cautious and jittery.

“I think it’s common sense,” Tabak said. “If you’re at a bus stop and you see a beer can in a bag, it probably isn’t a bomb. It could be, but it probably isn’t. If there’s a bunch of trash around and you see a beautifully wrapped box, something that looks out of place, then you should call the police.”

Times staff writer John Chandler and Times correspondent Dan Dow contributed to this story.