Yellow liquid sent to Russian Embassy

An official of the embassy found Wednesday morning an envelope with the container and the name of the sender as "captain of the Sekihotai," the police said. The liquid, however, is believed to be olive oil.

In October, letters containing red liquid from the same named sender were delivered to the Chinese Embassy in Tokyo and five other Chinese establishments in Japan. Police are investigating any link between the Chinese and Russian cases.

The name Sekihotai drew public attention when it appeared in connection with a shooting incident, in which an Asahi Shimbun reporter was killed and another person was injured in Hyogo Prefecture in 1987.

On Nov. 1, Russian President Dmitry Medvedev visited one of the four disputed islands off Hokkaido, called the Northern Territories in Japan and the Southern Kurils in Russia, sparking anger among many Japanese.

The four islands, the Kunashiri, Etorofu, Shikotan islands and the Habomai islet group, were seized by the Soviet Union following Japan's surrender in World War II. Japan claims the islands have been occupied illegally.