The Australian authorities have vowed to end a dance music festival after two people died of a suspected drug overdose.
New South Wales police said 700 sought medical help for drug problems in Sydney's Defqon. 1 and 3 people are in critical condition.
Prime Minister Gladys Berejiklian called the annual event uncertain and should not take place again.
Organizers Q-Dance Australia said they are working with the authorities.
The two dead were not named, but they were both in their 20s and died after the collapse in the hospital, police said.
"I am absolutely appalled by what happened …" Ms. Berejiklian said in a statement. "This is an unsafe event and I will do my utmost to ensure that it never happens again."
The police said ten people were charged with drug-related crimes, including two teenagers allegedly carrying 120 tablets at the event.
The Defqon 1 festival, which takes place at the Sydney International Regatta Center, mainly plays hardcore techno, house and trance music.
In recent years there have been two more dead at the festival. The event has been running since 2009.
"We do everything we can to make these events safe, and what we can not do is to be in people's minds, to be in the decision-making process of people using illegal drugs," said the deputy police chief Allan Sicard.