China fired a missile from a hypersonic weapon as it approached a target during a test in July, the Financial Times reported, adding the Pentagon was surprised because no nation was known to have the capability.

A hypersonic glide vehicle launched by China fired the projectile over the South China Sea while moving at five times the speed of sound, the newspaper reported, citing people familiar with the intelligence.

Some military experts believe an air-to-air missile was fired, the newspaper said. Others thought it was a countermeasure that could hurt the ability of missile defense systems to knock out the hypersonic weapon, which can carry a nuclear warhead, in a battle.

The Financial Times reported last month that China conducted hypersonic weapons tests on July 27 and again on Aug. 13, raising concern in Washington about Beijing’s advancing military capabilities. China’s Foreign Ministry said the nation had tested “a routine spacecraft” to see if it was reusable.

If China’s tests of hypersonic weapons are confirmed, it would suggest that President Xi Jinping may be exploring orbital strikes as a way to counter American advancements in shooting down ballistic missiles before they can threaten the U.S. homeland. Last year, the U.S. Navy successfully intercepted a mock intercontinental ballistic missile.

“I certainly can’t think of any technical precedent to a hypersonic glide vehicle releasing some sort of payload — implied to be a missile by the FT story,” said Ankit Panda, the Stanton senior fellow in the nuclear policy program at the Carnegie Endowment for International Peace.

“I do wonder, however, if this ‘missile’ may have been some other sort of payload, perhaps a countermeasure or some other sort of support mechanism,” he said. Panda added there are questions about the military utility of such a demonstration, and the international community shouldn’t assume China intends to deploy such a weapon in the field.