TOKYO (Reuters) -A man holding what appeared to be a knife attacked a bus used by a Japanese school in Suzhou, China, on Monday, seriously wounding a Chinese woman and injuring a Japanese woman and her child, an official at the Japanese consulate in Shanghai said.

The Chinese woman, who was aboard the bus, is in critical condition, while the injuries sustained by the Japanese woman and her preschooler child, who were waiting for the bus at a stop, are not life-threatening, the official told Reuters.

Asked whether strained ties between Japan and China could be behind his action, the official declined to comment and said local authorities have already taken the man into custody and are conducting investigation.

(Reporting by Kiyoshi Takenaka, Editing by Angus MacSwan)