Kawasaki is stepping up security measures near a community center located in one of its largest Korean neighborhoods after the facility received a New Year's card threatening to "exterminate" ethnic Koreans living in Japan.

At the heart of the threat is Fureaikan, a community center established in 1988 by the city in its Sakuramoto district — home to many ethnic Koreans — as a hub of cross-cultural communication between Japanese and foreign residents.

Earlier this month, the facility received a New Year's card with a message — written in strange, blocky Japanese characters and looking as though they had been drawn with a ruler — that began with a chilling sentence: "Let Zainichi Koreans be exterminated from the face of the Earth." It then went on to say, "If there is anyone left alive, let them be brutally killed," according to Fureaikan.