Youth support groups on the Gold Coast have expressed concern about alcohol consumption at Schoolies as images of the massive weekend clean-up have emerged. Queensland Police, however, is praising the teens for their good behaviour, saying only four arrests were made over the weekend. Red Frogs national Schoolies coordinator Chris George said he observed "quite a drastic increase" in alcohol consumption. "We've seen that a lot over the last 25 years but this year's is particularly confronting for us, just how much alcohol is being purchased and brought in," Mr George said. Red Frogs is a not-for-profit organisation designed to support young people tackle drug and alcohol use safely. The group is a mainstay for Schoolies celebrations around the country, offering training and advice in the lead-up to the event and on-the-ground support. There are about 20,000 teenagers at the event. Red Frogs estimates around 50 per cent of attendees are younger than the legal drinking age and that hotel rooms had become a site for underage drinking. "We're seeing a lot of 18 year-olds purchasing alcohol and coming up to the hotel rooms before they head out to celebrate on the beach." "We did get quite a few phone calls last night from Schoolies needing support where their friend had consumed too much alcohol" Mr George said. IN OTHER NEWS: Police are hoping metal detector 'wands' will catch attendees carrying weapons, with three adult revellers caught with knives this weekend. Queensland police have extra patrols on during the two week event. Extra physical and mental health professionals are also around to help Schoolies suffering adverse drug or alcohol reactions in a 'judgement-free zone'. The celebrations are set to close after NSW and Victorian students leave on December 4.