North American actress Pamela Anderson has joined forces with animal rights campaigners in a bid to free apes kept in "squalid\’ captivity in the U.S. state of Florida.

Anderson has written an open letter to Florida governor Charlie Crist, targeting \’road-side zoos\’ in the state, where she claims chimpanzees and other animals are kept in inadequate enclosures.

The actress warns a tragic accident – like the chimpanzee attack in Connecticut in February that left a woman maimed – is just waiting to happen.

Anderson – a regular campaigner for People for the Ethical Treatment of Animals (PETA) – writes, "With so many frustrated great apes stewing in squalid facilities in Florida, it is only a matter of time before a similar tragedy strikes your state. PETA and I appeal to you to take action to prevent Florida\’s roadside zoos from keeping great apes and to ensure that these intelligent primates are transferred to approved sanctuaries to live out the remainder of their lives in suitable surroundings."