A southeast Siberian region recovering from weeks of deadly flooding has been hit by another plague: venomous vipers. Twenty-five people have died and seven people remain unaccounted for since the floods, described by scientists as the biggest in 180 years, hit the Irkutsk region in late June. Vipers were spotted almost immediately afterward and officials had warned residents to exercise caution outdoors.

Increased viper sightings have prompted authorities in at least one of the region’s districts to renew their warnings. “The danger of being bitten has not been ruled out at all. We have only five doses of the antidote in the area,” the Chunsky district said in a statement Friday. Meanwhile, a man in the central Russian region of Chelyabinsk has reportedly died from a snakebite while waiting for doctors to deliver the anti-venom medicine.