More than 100 hippos have mysteriously died within a week in Namibia. As of yesterday, October 9, 107 hippos had been reported dead, and the lethal disease anthrax is likely to blame.

The hippos have died in the Mahango area of Bwabwata National Park in the Kavango East Region of Namibia. The Ministry of Environment and Tourism (MET) believes that anthrax is the cause but is waiting for veterinary assessments to confirm this.

“This is a situation that we have seen before. It happened in Zambia before and it mainly occurs when the level of the river is so low… Our scientist will advise properly, but we suspect it is anthrax,” Colgar Sikopo, the MET’s director of parks and wildlife management, told Namibian newspaper New Era.

The newspaper also tweeted a picture, in which a number of lifeless hippos can be seen lying on their backs.

Anthrax can normally be found in soil, infecting animals as they graze, or in shallow stagnant water like the low river in the national park. As hippos spend a lot of time in the water, they are particularly at risk.

Anthrax is caused by the bacteria Bacillus anthracis, which is found in arid climates. Generally, it doesn’t spread very easily, but it can infect both wild and domestic animals, and sometimes even people.

Anthrax can spread to carnivores that have eaten infected meat, so officials are worried about the health of crocodiles that might have feasted on the deceased hippos. They are also warning local people to avoid the dead animals and not to consume their meat.

“What we are doing is we are trying our best to burn every carcass to prevent further spreading of the disease, but also to ensure that no person gets to these animals and starts feeding on the meat,” said Sikopo.

This is the first time that this kind of mass die-off has been observed in Bwabwata National Park, but similar events have happened before in Uganda’s Queen Elizabeth National Park in 2004, where roughly 300 hippos died, and again in 2010, when 82 hippos and nine buffalo were killed.

Officials are hoping they can control this latest outbreak and are telling locals not to worry. “This is a natural cause and with the animals dying people should not panic, as it won’t negatively affect tourism in the area,” Sikopo said.

Before the deaths, the entire hippo population of Namibia was just 1,300, so hopefully the outbreak will be controlled soon.