The Tokyo Metropolitan Police Department Public Security Bureau (警視庁公安部 Keishichō-kōanbu) is a bureau of the Tokyo Metropolitan Police Department in charge of public security with jurisdiction over the Tokyo metropolis. It has a force of more than 2,000 officers. The PSB is not a Japanese version of Federal Bureau of Investigation, despite some claims that it is. It does not concern with ordinary criminal activities. It main focus is activities which threaten national security and therefore, the purpose is much similar to MI5. However, unlike MI5, it is operated entirely by police officers.