The U.S. Submarine USS Connecticut knocked into a Chinese underwater mountain, also called a seamount, in the South China Sea on Tuesday. Two anonymous US navy officials reported the incident, but they have not yet explained why the incident occurred or how much damage was incurred to the seamount.

The Foreign Ministry spokesman Wang Wenbin has criticized the US military for not giving an explanation for why the USS Connecticut was in the South China Sea in the first place and where exactly the incident occurred. China has claimed control over the South China Sea since the 1970s.

The crew of the USS Connecticut sustained minor injuries, and the submarine traveled to Guam to assess the damage. The Navy has reported that the nuclear reactor and the propulsion system of the submarine have not been damaged.

Foreign Ministry spokesman Wenbin has stated that the US has a clear “lack of transparency and responsibility.” At a briefing about the incident, Wenbin encouraged the US “to give a detailed account of the incident.”