Washington CNN  — 

A US nuclear-powered submarine that struck an underwater object in early October had hit an uncharted underwater mountain, an investigation found, forcing it to head from the South China Sea to Guam for repairs.

The USS Connecticut had been operating in the contested waterway when it struck the object on October 2, but it was unclear at the time what it had hit.

“The investigation determined USS CONNECTICUT grounded on an uncharted seamount while operating in international waters in the Indo-Pacific region,” a 7th Fleet spokesperson told CNN in a statement. US 7th Fleet operates in the Western Pacific and Indian oceans.

Though the Seawolf-class submarine suffered some injuries to crew members and some damage, the Navy said the nuclear propulsion plant was not damaged in the accident. None of the injuries were life-threatening.

The command investigation for the USS Connecticut has been submitted to Vice Adm. Karl Thomas, the commander of 7th Fleet, for his review, according to the statement. Thomas will decide whether “follow-on actions, including accountability, are appropriate.”

USNI News was the first to report the findings of the investigation.

The collision came at a particularly sensitive time in US-China relations, as the Chinese military was sending waves of aircraft into Taiwan’s Air Defense Identification Zone. On the day of the crash, China flew 39 aircraft into the Air Defense Identification Zone. Two days later, China flew a record 56 aircraft into the zone in a 24-hour period.

Though the number of incursions ebbed for a short period, they have since begun again. On Sunday, Taiwan’s Ministry of Defense said eight People’s Liberation Army aircraft entered the Air Defense Identification Zone, with another six flying in on Monday.

Meanwhile, the tensions between Washington and Beijing have increased. Last week, US Secretary of State Antony Blinken called for Taiwan to have “meaningful participation” at the United Nations, calling Taiwan’s participation “not a political issue, but a pragmatic one.”

The statement drew an angry rebuke from Beijing, which views unification with the independently ruled island as one of its primary objectives and adamantly opposes Taipei’s participation in international forums.

“Should the US side choose to continue playing the ill-advised ‘Taiwan card,’ it would inevitably pose seismic risks to China-US relations, seriously undermine peace and stability across the Taiwan Strait, and gravely harm the interests of the US itself,” Foreign Ministry spokesman Zhao Lijian said a day after Blinken’s statement.

Zhao also said that Taipei’s current policy is “the greatest realistic threat to peace and stability across the Taiwan Strait.”

On Thursday, Taiwan’s defense minister openly acknowledged that US military personnel are training Taiwanese troops.

“The US military is only assisting in training (our troops), but they are not based here,” Chiu Kuo-cheng said, according to Taiwan’s official Central News Agency.

CNN’s Eric Cheung, Steven Jiang and Jennifer Hansler contributed to this report.