SHENYANG, June 9 (Xinhua) -- China's unmanned submersible Haidou-1 has recreated the country's deep-sea diving record by submerging 10,907 meters under the Pacific Ocean surface of the Mariana Trench.

Members of the expedition team from the Shenyang Institute of Automation with the Chinese Academy of Sciences told Xinhua that the vehicle dived over 10,000 meters four times at the Challenger Deep in the Mariana Trench during the trip.

The team left for the expedition on April 23 and returned to the northeast China province of Liaoning on Monday.

During the deep-sea diving operation, researchers tested high-precision depth detection, machine hand operation, acoustic detection and positioning, and high-definition video transmission.

The submersible collected samples from the deep sea and captured high-definition images of the geological environment.