Three lions have died at a Tokyo zoo and several more have fallen ill, most likely due to extreme heat, following several weeks of record-breaking temperatures across Japan.

The park¡¯s lion exhibit had been suspended since July 23 after several of the big cats showed signs of sickness, such as loss of appetite, fatigue and decreased activity, in mid-July, Tokyo¡¯s Tama Zoo said in a statement Monday.

The three lions that died were all female: Mugi, age 3, Ichigo, age 11, and Luena, age 15. The zoo had a total of 16 lions, including five males, as of July 18.