Seven people have died of suspected drug overdoses at a music festival in Vietnam.

Five others were in comas following the event, according to the state-run Capital Police newspaper.

The music festival was attended by thousands of people and was held in a water park near Hanoi's city centre.

Police seized suspected drug substances at the scene.

The newspaper wrote that all the people who overdosed had tested positive for drugs but did not identify which substances were used.

Local officials and police officers were not available to comment on Monday.

Government data suggests that Vietnam has 220,000 drug addicts with police records.

Around 1,600 people die each year in the country from a drug overdose.

Heroin and methamphetamine are the most commonly used substances in Vietnam, with authorities noting a recent rise in the use of the latter drug.