A Chinese submarine was seen in satellite images with its nuclear ballistic missile hatches open as it sat on the pier of a naval base with underground facilities overlooking the contested South China Sea.

According to the latest satellite image updated by Google Earth Pro, a powerful desktop software version of Google Earth, a submarine was seen docked with at least four submarines at one of the quays of Longpo Naval Base on Hainan Island to the south China’s missile hatches are not closed.

User @benreuter_IMINT, an open source intelligence analyst active on to transport 12 long-range missiles for nuclear attacks.

Newsweek The Chinese Defense Ministry emailed for comment.

Longpo is known to be home to China’s Type 094 submarine fleet. It is equipped with six 754-foot-long berths for berthing twelve submarines, and an underground base protects them from attack and surveillance. Newsweek previously reported on the base’s activities after reviewing satellite images.

In a 2023 report, the Pentagon said that the Chinese military – which has the largest navy in the world with more than 370 ships and submarines – equipped each of its Type 094 submarines with either the submarine-launched JL-2 or JL-3 ballistics equip missiles that serve as the country’s sea-based nuclear deterrent.

The ranges of the JL-2 and JL-3 missiles are 3,900 and 5,400 nautical miles, respectively, the Pentagon estimated. The former can attack the East Coast of the United States from waters east of Hawaii, while the latter could attack parts of the US mainland from China’s waters.

China likely conducted “near-continuous maritime deterrence patrols” with its Type 094 submarines, the report said. Meanwhile, American nuclear submarines are constantly on patrol, making it difficult for adversaries to track them all, contributing to their survivability, according to a 2020 US Defense Department fact sheet.

Collin Koh, senior fellow at the Singapore Institute of Defense and Strategic Studies, said on X that the new satellite image was a rare image. This also “further substantiates the reports of regular strategic deterrence patrols by these SSBNs,” he added, referring to Chinese nuclear ballistic missile submarines.

Chi Guocang, a former Chinese submarine officer who taught at the country’s submarine academy, said the South China Sea, where China has territorial disputes with its neighbors, is a good place for China’s nuclear submarines to maneuver and hide from the US’s allied forces.

About the South China Sea, he said earlier this year: “The average water depth is more than 1,200 meters and the sea area is quite large. There are many islands, reefs, sandbanks and trenches. The underwater geographic environment is complex.”

Beijing has never disclosed its nuclear weapons inventory. In 2023, the US military estimated that the country had more than 500 warheads. The Bulletin of Atomic Scientists said at least 72 Chinese nuclear warheads had been assigned to the submarine-launched ballistic missiles.

The latest satellite image, taken on December 7, also showed a crane working from the dock over the submarine’s open hatches. It was not immediately clear whether this was a ballistic missile loading or unloading operation, as @benreuter_IMINT said in the post on X.

Tom Shugart, a former U.S. Navy submariner and adjunct senior fellow at the Center for a New American Security, said some other maintenance work.