Three female lions died within a week at Tama Zoological Park in Hino, in the greater Tokyo metropolitan area, as severe heat affected parts of Asia. The zoo suspects heat stress as a preliminary cause. Three-year-old Mugi died on July 28, 11-year-old Ichigo died three days later, and 15-year-old Luena died on Sunday.

The zoo closed its lion exhibit in late July after several animals showed symptoms including loss of appetite and lethargy. Staff sprayed water, used large industrial fans and administered intravenous fluids to cool and treat the animals. Ten lions received treatment; four are recovering while three remain ill. Officials said post-mortem examinations will determine the formal cause of death, although dehydration and signs of multiple organ failure were found in all three lions.

Some parts of Japan recorded temperatures of 40 degrees Celsius or higher for five consecutive days in late July. South Korea recorded 42.5 degrees Celsius in Yangsan on Sunday, its highest temperature in 122 years of weather records. The World Meteorological Organization warned that a strengthening super El Niño could raise the likelihood of above-normal temperatures in large parts of the world in coming months.