The organizers of an annual horse festival in Japan said Tuesday that they were considering changing the dates for the gathering next year, after sunstroke affected 111 animals, killing two of them.

Japan has recorded its hottest average July temperatures in over 100 years, and on Tuesday heatstroke alerts were in place in 26 of the country's 47 prefectures, with the mercury forecast to hit 38 degrees Celsius (100 degrees Fahrenheit) in places.

At least 111 horses — and dozens of people — needed treatment for sunstroke at the Soma Nomaoi festival in Fukushima Prefecture that took place from July 29 to 31, after temperatures touched 35 degrees, the hottest in five years.

Two of the horses died, the organizers said.

The annual three-day event — featuring more than 400 participants dressed as medieval samurai warriors fighting on horseback over flags that are shot overhead by fireworks — attracted more than 120,000 people, reports said.

Yoshichika Hirata, a member of the festival's executive committee, told AFP that changing the date of next year's event to a cooler time of year would be discussed at a meeting on Thursday.

"We sprinkled water on the track for the first time, as extreme heat was expected. We used three water-sprinkler cars, but it dried up quickly," Hirata said.

One horse died during last year's festival, after which a majority of riders supported a plan to change the date, according to a survey conducted in December.