As the New York International Auto Show opens its doors to the public tomorrow, law enforcement officials and car companies will be ramping up security — and concerns go beyond terrorist threats.

In the past decade, the week-long auto show at the Jacob K, Javits Convention Center has been the site of a stabbing, numerous thefts, such as of gas caps and fuses, and multiple acts of vandalism, including slashed cushions and key-scratched doors, an official at General Motors who works at the convention each year said. The official asked not to be identified.

There has been a distinct increase in security levels over the past three years, since an alleged gang member was arrested for inciting a riot in 2004, Sergeant Ken Cano of the New York State Police, the department in charge of policing the state-run convention center, said.

As the press descended on the convention center yesterday, security was light. It isn’t until Friday, when the show is opened to the public that crimes generally occur, officials said. Mr. Cano said Easter Sunday is an especially popular day for criminal activity.

To bolster the state police and convention center security, auto companies take special precautions in preparation for the event, the president of the New York International Auto Show, Mark Shienberg, said.

“The manufacturers take everything off the car that can move, like stick shift knobs and gas caps,” he said. “One year we actually saw a tire getting wheeled out of the center.”

While crime does occur at the auto show, Mr. Sheinberg is quick to point out that in most instances the offenses are minor thefts and vandalism, which he says are inevitable at a 10-day event that last year drew about 1.2 million people.

The most devastating criminal incident to date at the auto show was a stabbing that took place in 1996, several officials said. Two men ended up in St. Vincent’s Hospital with stab wounds after an argument broke out at a BMW exhibit, the New York Times reported.

It is generally the high-end automobiles and after market exhibits, which display custom car parts, that draw the most attention from raucous attendees, officials said.

Bentley Motors Limited hires a private security staff for the event, a precaution the car manufacturer takes at every auto show, a spokesman for the company, Peter Reuter said.

“The way we monitor and handle it is to be careful with who is coming on to the show stand,” he said. “Our display is set up so we keep the flow moving.”

Although the event doesn’t open to the public until tomorrow, police have already made two arrests — of protesters charged with disorderly conduct, Sergeant Cano said. Jeremy Wells, 36, and John Waterberg, 29, both from New York City, were apprehended after scaling the front of the convention center and displaying a 20-foot banner that challenged Toyota to become an environmental leader, he said.