Hello Kitty theme park in Tokyo closed after terrorist threat

A Hello Kitty theme park in Tokyo has been forced to close for the day after it received a "terror threat," its operator said.

Sanrio Puroland, also known as Hello Kitty Land, is located in Tama New Town in north Tokyo. In a statement published on the park's official website, operators said they received "a terrorist threat email" on Saturday.

"As we are unable to adequately ensure the safety of our customers, performers, and on-site staff, we have decided to temporarily close," operators said.

An official police report was filed and refunds for tickets on Saturday are being considered, they added.

"With cooperation from the police, we were able to verify that there are no longer any safety threats; therefore we will resume normal operations on February 25."

"We appreciate your understanding and cooperation. We apologize for the inconvenience caused... (and) will continue to work hard to ensure that everyone can enjoy the event with peace of mind."

Police did not find any suspicious objects, according to a report by Japanese broadcaster NHK and cited by Reuters.

Hello Kitty is one of the most famous and recognizable Japanese brands of all time.

Created in 1974, the cartoon cat's appeal has been instrumental in spreading "kawaii" Japanese pop culture overseas.

Founding company Sanrio has grown into a retail and entertainment behemoth with amusement parks and restaurants throughout Japan, the United States and the United Kingdom.

Sanrio Puroland opened in 1990 and attracts over 1.5 million visitors per year - making it one of Japan's most popular theme parks, along with Tokyo Disney Resort.