RENO, Nev. (AP) — An animal rights group is urging federal inspectors to fine Charles River Laboratories nearly $200,000 after the firm reported that four more monkeys and other research animals died in its care at its testing labs in Nevada and elsewhere.

Leaders of the Stop Animal Exploitation Now say the most recent deaths demonstrate a continuing trend of negligence that has resulted in deaths of research animals. The group stepped up its scrutiny of the labs after 2008 when a heating malfunction killed 32 monkeys in Sparks and another was boiled alive a year later when it was mistakenly left in a cage that went through a washer at the Reno lab.