KUNMING, July 15 (Xinhua) -- Ten suspects have been caught and more than 30 kilograms of heroin seized in a drug trafficking case, police in southwest China's Yunnan Province said Sunday.

The capture was the result of a joint-operation by police in Yunnan and northwest China's Gansu Province.

At the beginning of the year, police in Yunnan's Dali Bai Autonomous Prefecture received a report that a drug gang was planning to smuggle drugs into China and transport them to Linxia Hui Autonomous Prefecture in Gansu.

A van was stopped by police at a toll station in Gansu on Thursday. Some 81 packages of heroin, weighing 30.8 kilograms in total, were found in the van. Six suspects were detained at the scene.

Another four suspects from the same gang were detained in Dali.

Further investigation is underway.

Yunnan has always been the main focal point of the national anti-drug campaign as it borders the Golden Triangle known for drug production and trafficking.

A total of 5,648 suspects have been arrested and more than 11 tonnes of drugs have been seized by police in Yunnan between January and May.