BATON ROUGE - BREC's Baton Rouge Zoo confirmed Wednesday that three spot-nosed guenons are dead after a group of dogs broke into the zoo Tuesday morning and attacked the monkeys.

Zoo Director Kaki Heiligenthal said surveillance video shows a couple of domestic dogs inside the zoo early Tuesday morning. The dogs made their way to the spot-nosed guenon exhibit. The dogs were able to get close enough to the monkeys to grab the monkeys' arms as they reached out of the cage. 

officials are still trying to find the dogs and determine how they got into the zoo Tuesday morning.

Zoo officials say the perimeter fence is regularly monitored and was checked less than two weeks ago.

Zoo keepers found two monkeys, a 22-year-old male and 29-year-old female, dead inside of their exhibit. A third monkey, an 18-year-old male, was also injured and was later euthanized.

The monkey’s death comes after inspectors from the American Association of Zoos and Aquariums concluded in May that the zoo was not at fault in the death of a pair of elderly giraffes earlier this year.

The zoo hopes to replace the giraffes but says there's not currently a timetable to make that happen.

With the monkeys dead, 21 animals have died since the start of 2016.