SAO PAULO (AFP) - Brazilian activists on Friday stormed a laboratory in the southeastern state of Sao Paulo and freed some 200 Beagle dogs used for drug testing, press reports said.

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 websites of the dailies Folha de Sao Paulo and O Estado de Sao Paulo.

Rat fetuses were also found during the operation which occurred at the Royal Institute lab located in Sao Roque, 60km from Sao Paulo. Police made no arrests.

The lab was not available for comment.

Ms Giulana Stefanini, one of the animal rights protesters who took part in the action, was quoted as saying that one of the beagles "was found with no eyes." Ahead of their action, the activists went to police to complain of 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 as "an act of terrorism," insisting that its activities are monitored by Brazil's Health Surveillance Agency, according to O Estado.

Animal testing for scientific research is legal in Brazil and is regulated in line with international norms.