Five meerkats have died in suspected dye poisoning at the Philadelphia Zoo

All five meerkats at the Philadelphia Zoo died within days, leading zoo officials to suspect that a dye may have poisoned them.

All members of the South African family of mongooses became ill and died within a month.

Their names are Nkosi, Lula, Nya, Kgala and Ari, and they were all brought to the zoo in 2013 as siblings.

An autopsy is underway, but officials believe they may have accidentally consumed a dye used to mark them.

“We suspect they accidentally consumed something toxic,” said Amy Shearer of the Philadelphia Zoo.

She said the dye used to identify the animals, Nyanazol D, was specifically the culprit.

“We’ve been using this animal dye… for over 30 years,” she told CBS News.

Rachel Metz, the zoo’s vice president of animal health, said staff were struggling to deal with the deaths.

“So there is a real, legitimate relationship that they feel with the animals, and they are clearly devastated now.”

The dye was used on the meerkats on June 1, according to the Associated Press. One was found dead 30 minutes later and the other four began showing signs of illness soon after.

Zoo officials are now coordinating with the USDA and the Association of Zoos and Aquariums to determine the cause of the animals’ deaths.

The Philadelphia Zoo, which calls itself “America’s First Zoo,” opened in 1874 and currently houses more than 1,900 animals, according to its website.

Elsewhere, and in happier news, the Smithsonian Institution’s National Zoo in Washington, D.C., announced last month that it was celebrating the birth of its first baby meerkat in 16 years.

The three puppies are two weeks old and are starting to open their eyes and explore their habitat. Guardians say the newborns were breastfed by mother Sadie and they appeared to be healthy and strong.