TOKYO: A popular Hello Kitty-themed amusement park in Japan closed for the day on Saturday after receiving an "email threatening terrorism," its operator said.Sanrio Puroland in the capital Tokyo is known for its rides, shows, and cutesy cartoon mascots, including the beloved feline-like heroine. "Today, Saturday, Feb. 24, 2024, we received an email threatening terrorism," the indoor theme park said in a message on its website."We decided to temporarily close for the day because the safety of visitors, performers and staff cannot be guaranteed at the moment," it added.The unspecified threat prompted police to scour Sanrio Puroland for suspicious objects, but none were found, public broadcaster Japan Broadcasting Corp. reported.Authorities were trying to identify the sender of the email, it said, citing unnamed police sources.Tokyo-based Sanrio created the ubiquitous pink-bowed character Hello Kitty in 1974 and opened the Sanrio Puroland theme park in Tokyo's Tama City in 1990.The threat against the popular tourist attraction and its closure sparked groans on social media, with one user annoyed it happened during a holiday weekend. "It's unforgivable that someone is doing this during a precious three-day weekend!" the user posted on X, formerly Twitter.