TOKYO — A Japanese farmer who was playing Pokémon Go while driving struck two women, killing one of them and badly injuring the other, in the country’s first fatality related to the blockbuster smartphone game.

Authorities in Japan — which is home to Niantic, the maker of Pokémon Go — had been concerned about the potential for accidents on roads and on crowded train platforms.

Those fears materialized Tuesday night when Keiji Goo, a 39-year-old farmer, was playing the game while driving a small truck in Tokushima prefecture on the island of Shikoku.

He struck two women while they were crossing the road, killing 72-year-old Sachiko Nakanishi and breaking the hip of 60-year-old Kayoko Ikawa. Goo told Tokushima police that he had been playing the game while driving, the Kyodo news agency reported.

“I was playing Pokémon Go while driving, so I didn’t really see what was in front of me,” the public broadcaster NHK quoted the driver as telling police when he was arrested.

There have been numerous accidents relating to Pokémon Go around the world since its release last month — including a man who crashed into a tree in New York state and an Australian man who drove into a school building.

This prompted the game developer to add a warning earlier this month not to play the game while driving. The app also detects when the player is moving quickly, sending another warning to check that the person is really not driving.

A previous update to the game included a change to the scanning technology for finding Pokémon, the website Geekwire reported. That made it less likely that Pokémon would appear for players traveling in a car rather than on foot.

This is Japan’s first fatal accident involving the game, the National Police Agency said Wednesday.

Before the game was released July 22, the government’s National Center of Incident Readiness and Strategy for Cybersecurity issued an illustrated, nine-point warning about playing the game.

The warnings included to watch out for heat stroke and to carry extra battery power, as well as advising against playing while walking or biking.

Still, official statistics show that police gave out 1,140 tickets for traffic violations involving Pokémon Go in the month since the game was released in Japan, 95 percent of them for playing while driving.

There had been 79 bicycle and car accidents linked to playing the game in that month, the National Police Agency statistics showed.