MILAN, Italy (AP) - Police fired tear gas bombs into a crowd of 1,000 stone-throwing youths who tried to break into a tent-theatre during a performance by Canadian singer Joni Mitchell, police said yesterday.

Several youths and policemen were injured, none seriously, in the almost three-hour melee Monday night on the outskirts of Milan, police said. One car was set afire and others were damaged, and dozens of youths were taken into custody and released after identification.

Traffic in the area was blocked for hours, delaying ambulances carrying the injured to hospitals. Inside the theatre, the Canadian singer completed her concert for an audience of 7,000 people.