(CNN) Approximately 191 feral horses have been found dead in a stock pond on Navajo land in northern Arizona, according to Navajo leaders, who attributed the death to ongoing drought and famine.

"These animals were searching for water to stay alive. In the process, they unfortunately burrowed themselves into the mud and couldn't escape because they were so weak," Navajo Nation Vice President Jonathan Nez said in a statement on Thursday.

Some of the horses were found thigh- to neck-deep in the mud at the stock pond in Gray Mountain, according to Nina Chester, a staff assistant for the office of the president and vice president.

Hydrated lime will be spread over the animals to speed up decomposition. They will be buried on-site, the statement said.

The Navajo community in Arizona has had to contend with a growing feral horse population of about 50,000 to 70,000, according to the statement.

Read More