The Japanese labour authorities have issued warnings to a semiconductor company and a university for overworking their employees, the move coming in the country where the term "karoshi" - or death by overwork - was coined.

Several high-profile karoshi deaths in recent years have spurred a bout of soul searching in Japan and consequently a promise to prevent a repeat of such cases. Those who died included a young executive working for advertising giant Dentsu, an NHK political reporter, and a construction supervisor at the Tokyo 2020 Olympic Stadium.