HO CHI MINH CITY, July 2 (Xinhua) -- Vietnam launched many campaigns to crack down on crimes in the first half of 2018, thus uncovering a number of transnational drug trafficking rings, Minister of Public Security To Lam said on Monday.

Reporting at the Vietnamese government's teleconference with provinces and cities nationwide, Lam said crimes were curbed in the first six months, noting that 12,400 drug-related cases were investigated and handled, Vietnam News Agency reported.

During a raid in late June in Vietnam's northern Son La province, local police killed two kingpins of a ring which trafficked large amounts of heroin from Laos to Vietnam. One of the two ringleaders, Nguyen Thanh Tuan from Hanoi capital, used phones to run many drug trafficking rings from distance in the last 10 years.

In 2015, Tuan escaped after one of his rings' members was arrested when transporting and hiding a total 490 cakes of heroin weighing over 170 kilograms in Hanoi. According to investigators, by 2015, his rings had trafficked nearly 1,200 cakes of heroin.

According to the minister, in the first half of this year, police probed into more than 54,900 criminal cases, including over 8,800 economic crime cases and 230 corruption cases. Over 12,800 environmental crime cases were also resolved.