SEEKONK — Spectators at the Seekonk Speedway threw rocks and bottles at the police and firefighters trying to come to the aid of two participants injured during the demolition derby Sunday night, according to police Capt. Craig Mace.

He said there were no arrests, however. One of those injured refused medical treatment and the second person was taken to a hospital by a private ambulance, Mace said.

Francis Venditti, general manager of the speedway, said yesterday that he was surprised to hear of such spectator behavior from a reporter. The police never brought such an incident to his attention, he said.

Mace said the evening of racing created “gridlock” on Route 6, particularly since motorists stopped to watch the fireworks that were part of the show. He said it took him about 45 minutes to travel one mile in late afternoon, shortly before the races were to start.