Nine people are in hospital with suspected overdoses after a rave party at Festival Hall in Melbourne last night.
Emergency services were called to the party called ‘I Am Hardstyle’ at around 11pm.
Police blocked the street off and the event was forced to end early.
Eight people were treated in the first aid area of the event, before a ninth person collapsed nearby.
At least four people are in critical conditions in hospital.
Ambulance Victoria’s state health commander, Paul Holman, sounded a dire warning about the drugs that are on Melbourne’s streets.
"Clearly these drugs are circulating now around the system," Holman said.
"Clearly they're dangerous.
"We've still got a big weekend of celebrations going on at a number of dance parties.
"Don't take these drugs, they will kill you.
"These are poisons. They (the users) don't know where they come from, they don't know what they do, and as we saw last night we had nine young people taken to hospital in a serious condition, poisoned by these drugs."