A weekend electronic music festival in Edmonton resulted in 27 people being taken to hospital with drug- or alcohol-related illnesses.

Four festival-goers were in serious condition and two were taken to hospital in critical condition, Alberta Health Services said Sunday.

The six more serious cases were related to the drug ecstasy or one similar to it, the agency said.

More than 8,300 people attended the event – billed as the largest one ever held in Western Canada – at the Northlands Expo Centre Friday and Saturday.

City police had imposed strict guidelines on the dance party, including drug and alcohol "amnesty" bins where people could dispose of their contraband before reaching security and drug-sniffing dogs.

"We can't stop them from consuming drugs in advance of coming to the event, or even drinking in excess before the event," Elements Electronic Music Festival spokesman Marcus Gurske told CTV Edmonton in a telephone interview.

Organizers wouldn't specifically address the number of sick people, but said they do everything possible to ensure a safe event.

One festival fan said there are more drugs on the street than inside the centre, while another said he didn't see any trouble and thinks the police did a good job.

The province's health agency had additional staff working at hospitals and extra ambulance staff on duty.

Organizers said the criticism was unfair and their event was like any other festival held in the city.

The festival paid about $145,000 for additional police services.

With a report from CTV Edmonton's Amanda Anderson