Well, they announced a rate hike in Japan, so that would seem to be a more immediate cause.
In fact, there’s some analysis that suggests that Japan’s rate hike contributes to the dip in the other markets. Evidently it was a thing for people to borrow yen, use that to get other currencies, and then buy stock and sell the stock to repay the loans. Since the yen has climbed 14% versus the USD in the past few days, those loans suddenly became awfully expensive.