Police in Hanoi said
Wednesday they had arrested four people for allegedly trafficking drugs across northern provinces.
According to police, the ring had transported over 33 kilograms of heroin from Son La province to Hanoi and Thai Nguyen province since 2010, before they were busted in August this year.
Police said on August 20, Trinh Van Bach, 37, was found carrying over 300 grams of heroin which he said he bought from Luong Duc Chinh, 45, for VND185 million (US$8,800).
Bach said he was planning to bring it to the southern region.
Later, police arrested Tran Luu Thuy, 39, who was accused of founding the ring in 2010 together with another man in Son La province.
The case is now under further investigations.