The accident happened as the cruise ship Costa Classica approached Shanghai after a three-day voyage from South Korea, Costa Crociere said in a statement, but the cause of the accident was not specified.

“Immediately after the accident, some passengers reported minor injuries to medical personnel on board. Three went to a Shanghai medical facility for further examination,” the statement said.

The ship sustained some damage on its starboard side, and the company cancelled a cruise bound for Hong Kong which had been due to start later the same day.