KIEV, Ukraine (AP) — Authorities in Kazakhstan says around one-third of the endangered saiga antelope population in this Central Asian nation has mysteriously died off in the last few days.

Kazakhstan's agriculture ministry said Friday the number of saiga that have died may have reached 85,000.

The ministry says it suspects the animals, which are recognizable for their distinctive humped snout, may have been struck by an epidemic of pasteurellosis caused by a bacterial infection. Officials say international veterinarian experts have been flown to Kazakhstan to study other possible causes for the catastrophic die-off.

The number of saiga plummeted in the 1990s as a result of poaching. At the latest Kazakh government count in 2014, the saiga population stood at 257,000.

Saiga are also found in smaller numbers in parts of Russia.