A teen-age boy was stabbed and critically wounded last night in the parking lot of Towson Town Center after an argument between two groups of youths turned violent, Baltimore County police said.

The 17-year-old, whose name was not released by police, was stabbed in the upper leg about 9 p.m. in the parking lot between the Hecht Co. and the Rain Forest Cafe.

The youth was flown by helicopter to Maryland Shock Trauma Center, where he was in critical condition early today, police said.

Baltimore County Police spokesman Cpl. Ron Brooks said the stabbing occurred after an argument between two groups of teen-agers inside the mall spilled out to the parking lot, near the entrance to the Hecht Co.

As the argument escalated between the two groups, each of about five youths, one teen-ager stabbed the other.

Brooks said investigators do not believe the stabbing was a random act and have leads and a description of the assailant. He was described as a male with gold front teeth in his late teens, wearing a black shirt and a dark baseball cap.

Violent crime is unusual at the mall, which is in the heart of Towson, but not unprecedented. Several mall employees have been robbed as they have tried to make night deposits, and patrons have occasionally been robbed in the parking lot and garage.

In January 2000, a security guard shot and wounded a robbery suspect after the man pointed a gun at the guard and a jewelry store clerk.

In September 1997, two women were charged with stabbing a third near a shoe display at Nordstrom Rack inside the mall.

Witnesses said the assault occurred after two of the women jostled while shopping, starting a dispute that escalated into pushing and shoving, and then the stabbing.