CHONGQING, May 25 (Xinhua) -- Nine people were killed and another 11 were unaccounted for as of Monday afternoon after heavy rain, which started on Saturday night, had battered Yongchuan District in southwest China's Chongqing Municipality, said local authorities.

Rescue and response efforts are still underway. The municipal and district-level flood control and drought relief emergency headquarters have so far dispatched a total of 1,827 rescue personnel of various categories.

From Saturday night to early Sunday morning, a sudden and extreme catastrophic rainstorm struck Yongchuan, triggering flash floods and geological disasters in multiple areas of this district.

Anxi Village is one of the worst-hit areas. Rescuers trekked across piles of accumulated mud and rock debris there, using life detectors to search for missing persons. In the meantime, some rescuers deployed large excavators and other engineering machinery in carrying out relief operations.

"We are conducting rescue operations via manual searches supported by engineering machinery, to ensure no area is left unsearched," said Guo Yufei, a rescuer. The rescue site has seen the use of 37 sets of remote-controlled excavators, 3D laser scanners and other equipment.

The disaster-stricken areas are marked by complex hillside terrain, a wide range of mud and rock deposits, large elevation differences, and high risks due to their proximity to river courses. Various technical means are deployed at the site to ensure safety in carrying out rescue work.

Guo said measures including low-altitude patrols by drones and close-range observation by safety officers have been adopted at the site to ensure the rescue work is done safely and efficiently.

Rescuer Yang Zulin was monitoring the slope stability with a slope radar, and the cloud map generated on the screen showed the deformation of the slope in real time.

"If we find that the slope has large deformation or is on the verge of sliding, we will issue an early warning to the site in time to ensure the safety of every rescue worker at the scene," Yang said.

As of 6 a.m., Yongchuan had provided accommodation for 2,141 residents from 1,113 households. A total of 42 resettlement sites had been set up across the district, with a total capacity of 9,005 people.

At the resettlement site of Shouyong Primary School in Banqiao Town, many disaster-affected residents were taking a rest. Sufficient daily supplies such as bottled water and food were available on site.

Liu Xiaoyan, a staff member of the resettlement site, said the resettlement area has provided sufficient supplies for affected people, ensuring that they have access to food, clothing, clean drinking water, safe shelter and medical services.