ISLAMABAD (AP) — Authorities said Friday they are investigating the deaths of a pair of lions that died two days apart during their transfer from an Islamabad zoo to an animal sanctuary in eastern Pakistan.

Anis Rehman, chairman of the Islamabad Wildlife Management Board, a government agency, said the lion and lioness were healthy when handed over to staff at a private animal sanctuary this week to transport them out of the Marghazar Zoo.

He said his organization was initially informed that a lion had died apparently due to “humid and hot weather” while being moved. But on Wednesday they learned the lioness had died.

“We have begun an investigation into this matter,” Rehman told The Associated Press.

He said animal caretakers lit a fire in the lions’ cage to spur them to move them to another cage but that the lions did not die due to suffocation, as reported on some social media.

The lions were brought to the zoo in May 2016 from Lahore Safari Park. They were being transferred on a court order after a finding that the animals were not being properly cared for.

Pakistan also plans to relocate a zoo elephant to a sanctuary in Cambodia after animal rights activists launched a campaign saying the pachyderm that spent three decades in the country was being mistreated at a zoo in Islamabad.