Over the past couple years, China has constructed artificial islands on reefs in the South China Sea, and populated them with a military barracks, a lookout tower, and even a runway. In January, the country landed a civilian plane at Fiery Cross Reef. In April, they turned on a lighthouse built at the northeast side of Subi Reef. But China isn’t only interested in building up from the sea – it’s also planning construction of a massive sea lab some 10,000 feet underwater, reports Bloomberg.

Although the project ranked second in China’s list of the top 100 science and technology priorities, the country has remained characteristically tight-lipped about its funding and timeline. However, Bloomberg reviewed a recent presentation by the Science Ministry that suggested the government was accelerating its plans.

Officially, the lab will be designed to help China search for minerals beneath the sea floor. “The deep sea contains treasures that remain undiscovered and undeveloped, and in order to obtain these treasures we have to control key technologies in getting into the deep sea, discovering the deep sea, and developing the deep sea,” President Xi Jinping said in May at a national science conference.

But tensions and territorial disputes surrounding the artificial islands have made some speculate about China’s true intentions. In its report, Bloomberg suggests that the underwater lab “may also serve a military purpose in the disputed waters.”

In fact, even Chinese Academy of Social Sciences’ senior researcher for Southeast Asian affairs, Xu Liping, echoed this sentiment. Xu told International Business Times that the underwater station was not intended as an affront to any nation or region. “China’s project will be mainly for civil use,” he added, “but we can’t rule out it will carry some military functions…Many countries in the world have been researching these kind of deep water projects and China is just one of those nations.”