GREENWICH, Conn. (AP) _ A truck driver and his passenger were arraigned Friday on charges of illegally transporting animals following a deadly trailer blaze that killed 50 puppies and injured 18 other dogs.

David Cook, 48, and Edward Earl Ruyle, 37, could also face 68 counts of cruelty to animals, but prosecutors may drop those charges if the fire is deemed an accident.

The blaze, which broke out Thursday night in a trailer being towed along Interstate 95, was apparently caused by a propane heater in the trailer, police said.

A total of 68 puppies _ including German shepherds, cocker spaniels and dachshunds _ were found, and the 18 injured dogs were taken to a veterinary hospital.

Although they had obtained the necessary paperwork to transport 67 of the animals, Cook and Ruyle were each charged with not having the proper health certificate to transport an additional white boxer puppy, police said.

The shipment of dogs, which originated in Arkansas, was to be delivered to pet stores along the East Coast.