A Chinese ship armed with a suspected electromagnetic railgun has reportedly been spotted on the high seas.

The same vessel armed with what appears to be the same weapon was seen earlier this year at a Chinese shipyard on the Yangtze River.

Unlike conventional guns, which rely on gunpowder, railguns use electromagnetic energy to propel projectiles forward.

A Chinese navy warship armed with what looks like a mounted electromagnetic railgun has apparently set sail, possibly for testing in the open ocean.

The Type 072II Yuting-class tank landing ship "Haiyang Shan" and its weapon were spotted along the Yangtze River at the Wuchang Shipyard in Wuhan earlier this year.

The latest photos of the test-bed ship, which appeared on social media a few days ago, show the ship toting the suspected railgun as the vessel roamed the high seas, Task & Purpose reported.

Chinese media outlets, such as the state-affiliated Global Times, said in March — nearly two months after the first pictures of what was dubbed the "Yangtze River Monster" showed up online — that the Chinese People's Liberation Army Navy is "making notable achievements on advanced weapons, including sea tests of electromagnetic railguns."

China is expected to field warship-mounted electromagnetic railguns with the ability to fire high-speed projectiles at targets up to 124 miles away by 2025, CNBC reported in June, citing US defense sources with direct knowledge of the latest military intelligence reports on China's new naval weapon.

China's railgun was first seen in 2011 and first tested three years later, according to CNBC. The Chinese military is believed to have successfully mounted the weapon on a navy warship for the first time toward the end of last year, when sea trials were suspected to have first started.

While conventional guns rely on gunpowder to propel projectiles forward, railguns use electromagnetic energy to hurl projectiles at targets downrange at hypervelocity, roughly 1.6 miles per second, making these weapons desirable next-generation combat systems.

Railguns require significant amounts of power, among other challenging demands. Whether or not China has managed to overcome these developmental issues remains to be seen.

China appears to be making progress as it moves toward mounting railguns on combat-ready warships, such as the new Type 055 stealth destroyers, rather than test bed ships like the Haiyang Shan. The US military, on the other hand, has yet to put the powerful gun on a naval vessel, even though railgun development began over a decade ago.

It is, however, unclear which country is leading the charge on this new technology, as very little is publicly known about China's railgun or its testing process. In the US, there is speculation that the Zumwalt-class destroyers could eventually feature railguns, which could be an alternative to the Advanced Gun System guns that the Navy might end up scrapping.

The destroyer is "going to be a candidate for any advanced weapon system that we develop," Vice Admiral William Merz, the deputy chief of naval operations for warfare systems, told the Senate Armed Services sea-power subcommittee last month.