Gladys Berejiklian has vowed to ban the Sydney Defqon.1 music festival after a series of suspicions of drug overdoses that left two young people dead and three fighting for their lives.
She said, however, that the government will not change its opposition to so-called pill tests.
"Anyone who defends the tests of pills is giving the green light to drugs that are absolutely unacceptable," he said.
Three people in critical condition
A Victorian woman, 21, and Sydney, 23, died after collapsing at Penrith's event on Saturday.
Three people, including a 19-year-old man, are seriously ill in the hospital, while 700 of the 30,000 attendees were seen by medical personnel, police said.
"I am absolutely horrified by what happened, I do not want any family to suffer the tragedy that some families are waking up this morning," the prime minister told reporters on Sunday.
"This is an unsafe event and I will do everything I can to make sure it never happens again."
The police urge people to take responsibility
Police said a 26-year-old Jamisontown woman remains in critical condition at the Nepean hospital, while the 19-year-old Artarmon man was airlifted to Westmead Hospital and is in intensive care.
A Newcastle man is also critically ill, while more than a dozen people were treated at the Nepean hospital for drug-related problems.
Toxicology reports are expected within a week to find out exactly what medications, if any, were taken by those who became ill.
Acting Deputy Commissioner Allan Sicard said that 180 police officers were at the event and that they had worked with the organizers to try to keep the revelers safe.
"What we can not do is be in people's heads, be in the decision-making processes of people when they decide to take drugs," he told reporters.
Doing business as usual is killing people: Greens
Deputy of the Greens, David Shoebridge, said the police presence at the festival was aggressive and called for festivals to introduce pill tests, amnesty containers and other damage minimization measures.
"We can not keep repeating the mistakes of the past," he said.
Mr. Shoebridge said that the police strategy so far had not worked and that it was necessary to change.
"Doing business as usual is killing people," he said.
The organizers reiterate the zero tolerance approach
The organizers of Defqon.1, having dealt with multiple deaths in the ten-year history of the event, warned ticket holders that the festival's drug policy was zero tolerance.
"This means that all types of soft and hard drugs are banned, if drugs are found, they will be handed over to the police," said a statement on the festival's website.
Police say 10 people were charged with drug offenses, including two 17-year-old girls who allegedly loaded 120 capsules "internally" at the scene.
Ecstasy, cocaine and GHB were some of the drugs confiscated from 69 people at the festival held at the Sydney International Regatta Center.
Local detectives have formed a new police attack force, dubbed Highworth, to investigate the two deaths.