One person was still on life support on Monday after more than two dozen people were taken to hospital from Sydney music festivals at the weekend suffering suspected drug overdoses.

At least 25 people aged between 16 and 25 were admitted to hospital on Saturday and Sunday following three events across the city.

In Victoria, six people suffering suspected overdoses were taken to hospital from the Rainbow Serpent festival. Two men, both in their 20s, were in a critical condition in Ballarat Base hospital and at least two others were in a serious condition, Ambulance Victoria said in a statement.

More than half of those treated in New South Wales needed attention on site from critical care medical teams, which the state government had sent to the Hardcore Til I Die, Rolling Loud and Electric Gardens festivals as part of a range of extra safety measures.

“I believe six of those ... had tubes down their throat to assist their breathing,” the NSW health minister, Brad Hazzard, told reporters in Sydney on Monday.

“There would have been parents, mums, dads, other family and friends wondering whether they would come home from those music festivals.”

Sarah Coombes from the NSW ambulance service said a number of those treated “likely would not have survived” had there not been increased medical support on site.

“Or, if they did survive, would not have survived neurologically intact,” she told reporters.

Dr Coombes said a majority of the patients came from Saturday’s Hardcore Til I Die event at Homebush.

A small number remained in hospital – most of whom were expected to make a full recovery, she said. “There’s one patient that’s still on life support.”

Police have charged dozens of people with drug-related offences across all three festivals.

Seven people have been accused of supplying drugs at the Hardcore Till I Die festival, including a 17-year-old Castle Hill boy who was allegedly found with 579 capsules and $2,075. He is due to face a children’s court on 20 February.

Another alleged supplier, 25, was allegedly found with 100 MDMA capsules and a knife, while a South Australian woman allegedly had 48 ecstasy capsules on her.

A further 16 people were due to face court for drug possession while 30 people were ejected for intoxication.

A total of 55 people were charged with drug possession and one woman accused of MDMA supply at the Electric Gardens festival in Centennial Park on Saturday, while 14 were charged with drug-related offences at Sydney Olympic Park’s Rolling Loud event on Sunday.

A 17-year-old girl is due to face court on 7 March accused of carrying 27 MDMA tablets and stolen goods, while 13 others were charged with drug possession.

The NSW premier, Gladys Berejiklian, whose government footed the bill for the extra protection, said she hoped and prayed people were starting to get the message not to take illicit drugs.