Animal rights activists have clashed with police the day after storming a laboratory in Brazil and freeing 178 beagles used for drug tests.
Some 500 people gathered to protest outside the Instituto Royal Lab Laboratory in Sao Roque, in the south-east of the country, and attempted a second raid on the facility.
Officer Edivaldo Nunes of the Sao Roque police department said the activists tried to break through barriers set up in front of the laboratory following Friday's raid.
He said: "They hurled rocks and set fire to a police car and to two cars of a local television station."
Police officers used tear gas and pepper spray to disperse the crowd but there were no reports of arrests or injuries.
On Friday a large group had stormed the building shouting "save the dogs" and driven away with the animals.
Most of the animals had their skins shaven and one was found dead, frozen in liquid nitrogen and with signs of mutilation, according to reports carried by the daily newspapers, Folha de Sao Paulo and O Estado de Sao Paulo.
Giulana Stefanini, one of the animal rights protesters who took part in the action, was quoted as saying that one of the beagles found had no eyes.
Ahead of their action, the activists complained to the police about the alleged mistreatment of animals at the lab, but they said no action was taken.
The lab cancelled a meeting with the protesters at the last minute and described the invasion on Friday morning as "an act of terrorism," insisting that its activities are monitored by Brazil's Health Surveillance Agency, according to O Estado.
Officer Edivaldo Nunes of the Sao Roque police department said none of the dogs have been recovered and no one has been arrested.
Animal testing for scientific research is legal in Brazil and is regulated in line with international standards.