Police are yet to confirm authenticity of the foreign media reports saying militant group Islamic State (IS) claimed responsibility for the killing of Japanese national Hoshi Kunio, reports UNB.It is not clear whether the news is authentic, said Nazrul Islam, assistant inspector general (Media) of police headquarters.He added a special team is working to confirm the truth of the news.Earlier, on Saturday, some foreign news media published reports saying that militant group IS posted a tweet on social networking site tweeter claiming responsibility for the killing of the Japanese citizen in Rangpur district.