Four nilgais in Islamabad Zoo die

Four blue bulls, also known as nilgais, who were kept at the Islamabad Zoo have died during the last week.

According to the zoo authorities, the cause of these deaths have not been ascertained yet. Tissue samples have been sent to a laboratory for testing and the cause will become clear once the report comes back, the administration said.

Another two nilgais are said to be in a critical condition.

The animals reportedly passed away because of the cold temperature and insufficient facilities at the zoo.