LHASA, June 6 (Xinhua) -- More than 2.8 million milliliters of blood have been sent to Tibet for medical assistance over the past year, the regional health authority said Wednesday.

The region's clinic blood supply has increased by 68.7 percent year-on-year, easing insufficient blood supply in the region.

Blood stocks were low for a long time due to the small population, and a relatively low pass rate of donated blood in the plateau region, said Dong Xiaorong from the regional blood center.

More than 500 doctors from other provinces have been sent to work in Tibetan hospitals since a medical assistance program was launched in 2015. With more operations, the volume of blood for clinic use is also increasing.

Blood banks in eight provinces and municipalities including Beijing, Shanghai, Guangdong and Jiangsu have established a regular blood transfusion mechanism to help Tibet since July 2017.