Metal pellets were apparently fired into a Japanese-Chinese language school in Tokyo over the weekend, and a razor was delivered last week to the Chinese Consulate General in Fukuoka.
Two pellets, about 5 mm in diameter, were found Monday at the school. Police suspect they were fired by a toy gun or a slingshot.
The developments are believed to be in retaliation to anti-Japan demonstrations in China in the past few weeks ostensibly over what Chinese claim are Japan's attempts to whitewash its wartime aggression and its bid to become a permanent member of the U.N. Security Council.
Four holes were found shortly before 7 a.m. Monday in the front door of the language institute, located on the ground floor of an annex to the Japan-China Friendship Center in Bunkyo Ward, and the two pellets were located nearby, police said. No one was injured, they said.
Police said they are investigating it as a case of property destruction.
The institute, founded in 1951 as a Chinese-language school aimed at helping promote exchanges between Japan and China, has also been offering Japanese-language courses for Chinese people studying in Japan since 1986.
Meanwhile, consulate officials in Fukuoka said Monday they received an envelope containing a letter protesting the anti-Japan demonstrations and a razor blade. It did not have the name of the sender, they said.