Picket line skirmishers with clubs and chains damaged 10 police cars and a driver crashed a steel plant gate Saturday after more than 1,600 union steelworkers at Gulf States Steel Inc. went on strike.

Several security guards at the plant sustained minor injuries, but state police said they didn't know how or when the guards were hurt.Workers began walking off their jobs after the old contract expired at midnight Friday. Four to eight pickets were at each of the plant's eight gates and no one crossed the picket lines, union spokesman Allen Stanford said.

Stanford said there was "just shouting back and forth but no one was hurt" in a picket line skirmish early Saturday, but police said 10 of their cars were damaged by clubs and chains and the tires on two units were slashed.

Around 3 a.m., police said, a motorist drove a van into a gate, destroying it, and then rammed a nearby small guardhouse, partially knocking it off its foundation. Police would not say whether the driver was arrested.

Despite the violence, state police Lt. James Hyatt characterized picketing as "very orderly most of the day." He said state troopers would be available through the night to assist city police.

Hyatt said troopers had made one arrest in connection with the strike. He said a man who was with the strikers at a plant gate was charged with failing to obey a lawful order and carrying a concealed weapon, a can of chemical Mace. Thermon Phillips, director of District 36 of the United Steelworkers of America, said he was unsure if supervisors were operating the plant, which makes steel plate and finished steel.

Company officials said they would have no comment Saturday.

Phillips said he expected an agreement to be reached "within a day or so" if negotiations continued as they have. Negotiatiors were meeting with federal mediators in Birmingham.

Earl Guyton, vice-president of United Steelworkers of America Local 2176, said negotiators had made some progress and would continue working toward an agreement with the maker of steel plate and finished steel.