The US Navy has sacked three top crew members aboard a nuclear submarine that crashed into an underwater mountain. Commander Cameron Aljilani and two others were removed after an investigation into the incident in the disputed South China Sea. The USS Connecticut struck the object last month, forcing the vessel to come to the surface for a week and sail to the US territory of Guam. Navy officials say the crew members "could have prevented" the collision. Last week, the navy said the submarine had hit an uncharted "seamount" while patrolling below the surface. A seamount is a mountain that rises from the ocean floor. Fifteen sailors suffered minor injuries. The submarine is currently being checked for damage at Guam in the Pacific before it returns to Washington for repairs. The incident happened amid rising tensions in the region. The USS Connecticut was operating in one of the most contested regions in the world. China claims most of the South China Sea, but surrounding countries and the US disagree. The incident happened just weeks after the US, UK and Australia agreed a historic security pact to share submarine technology in the Asia-Pacific, widely seen as an effort to counter China"s power. The crash angered officials in Beijing, who have questioned what the vessel was doing in the region, and said they were worried about possible nuclear leakage. At a press briefing on Friday, a Chinese foreign ministry spokesperson said the US needed to give a full account of the incident and "stop its provocation", Reuters news agency reported. US Navy officials have yet to explain how the vessel hit the seamount. Ryan Ramsey, a former British Royal Navy submarine captain, said he was shocked by the collision, which is relatively rare. "The USS Connecticut is a very modern submarine — so it"s kind of surprising," he told the BBC. "But if you relax at any point, then things can happen."