HANOI (AFP) - Five men were arrested in Vietnam for allegedly attempting to smuggle US$2.5 million (S$3.3 million) worth of heroin into China after police shot at their drug-packed vehicle as they tried to flee, local media reported on Monday (Feb 26).

The men were caught in northern Cao Bang province on the border with China with nearly 100kg of heroin from Laos in their truck, state-run Thanh Nien newspaper reported.

Vietnam is a key trafficking hub for narcotics from the "Golden Triangle" covering Laos, Thailand and Myanmar, one of the world's largest drug producing regions, and the latest bust is one of the largest in Vietnam in recent months.

The five Vietnamese men were arrested between Friday and Saturday as they tried to drive past police in the northern province, prompting "authorities to open fire", Thanh Nien reported.

Photos on state media showed the alleged ringleader, 31-year-old Tran Van Bang, standing with a large pile of heroin bricks.

The bust follows a similar seizure last month in northern Vietnam, where police confiscated 170kg of heroin worth US$3 million also from Laos, reportedly the largest-ever drug haul in the one-party state.

Vietnam has some of the toughest drug laws in the world. Anyone caught with more than 600g of heroin or more than 20kg of opium could face the death penalty.