A pack of stray dogs killed about 31 endangered blackbucks at a zoological park in the city of Kanpur, India.

The incident took place Saturday night after a group of stray dogs possibly entered the zoo through a damaged boundary wall, reports BBC.

The damaged wall was being repaired and the guards were using fence wires across the wall to stop anybody from entering the enclosure. However, the fence wires were not tied on Saturday. The dogs entered through the wall and attacked the blackbucks' enclosure, which was the closest to the wall.

"When they were attacked, they tried to escape but their enclosure was shut. Some were then killed by the dogs, many were injured, while others died of heart-attacks brought on by shock," chief wildlife officer Rupak De told BBC.

Zoo workers noticed two dogs eating the carcasses of the endangered species Sunday morning. Both dogs and another dog roaming the zoo were killed by forest guards.

De conducted an inquiry and submitted a report to the chief minister of Uttar Pradesh, following which officials, including director of the Kanpur zoo Praveen Rao, two forest guards, a keeper and a watchman were all suspended, according to a report in The Indian Express, an Indian newspaper.

Blackbucks are native to the Indian subcontinent. The population growth of blackbucks has significantly declined in the last 100 years due to human population growth and the increase in domestic livestock. The International Union for Conservation of Nature (IUCN) has listed the species as "Near Threatened", with the species already extinct in countries like Bangladesh, Nepal and Pakistan.

The species is protected in India by the Wildlife Protection Act of 1972.