There were no reports of casualties after an initial investigation, Beijing Tianbing, also known as Space Pioneer, said in a statement on its official WeChat account.
Parts of the rocket stage were scattered within a “safe area” but caused a local fire, according to a separate statement by the Gongyi emergency management bureau.
The fire has since been extinguished and no one has been hurt, the bureau said.
The two-stage Tianlong-3 (“Sky Dragon 3”) is a partly reusable rocket under development by Space Pioneer, one of a small group of private-sector rocket makers that have grown rapidly over the past five years.
Falling rocket debris in China after launches is not unheard of, but it is very rare for part of a rocket under development to make an unplanned flight out of its test site and crash.
According to Space Pioneer, the first stage of the Tianlong-3 ignited normally during a hot test but later detached from the test bench due to structural failure and landed in hilly areas 1.5 km (0.9 mile) away.
A rocket can consist of several stages, with the first, or lowest, stage igniting and propelling the rocket upward upon its launch.
When the fuel is exhausted, the first stage falls off, and the second stage ignites, keeping the rocket in propulsion. Some rockets have third stages.
Space Pioneer says the performance of Tianlong-3 is comparable to SpaceX’s Falcon 9, which is also a two-stage rocket.
In April 2023, Space Pioneer launched a kerosene-oxygen rocket, the Tianlong-2, becoming the first private Chinese firm to send a liquid-propellant rocket into space.
Chinese commercial space companies have rushed into the sector since 2014 when private investment in the industry was allowed by the state.
Many started making satellites while others including Space Pioneer, focused on developing reusable rockets that can significantly cut mission costs.
The test sites of such companies can be found along China’s coastal areas, located by the sea due to safety reasons.
But some are also sited deep in the country’s interior such as Space Pioneer’s test center in Gongyi, a city of 800,000 people in the central province of Henan.