China has secretly installed anti-ship cruise missiles and surface-to-air missile systems on three of its fortified outposts in the South China Sea, a report said Wednesday, as Beijing seeks to further project power in the disputed waters.

CNBC, citing sources with direct knowledge of U.S. intelligence reports, said that the missile platforms had been moved to outposts on the Spratly group of islands within the past 30 days. Such a deployment would be the first to the Spratlys, which are located some two-thirds of the way east from southern Vietnam to the southern Philippines. Several Asian nations, including Vietnam, Taiwan and the Philippines, have rival claims there.

If confirmed, the placement of the defensive weapons would come on the heels of China's recent installation in the South China Sea of military jamming equipment, which disrupts communications and radar systems.