School’s out for summer has taken on a new twist in Spain after vacationing high school students triggered a major COVID-19 outbreak on the Mediterranean island of Mallorca last week. The partying teens celebrating the end of their university entrance exams created a “perfect breeding ground” for the virus as they mixed with others from around Spain and abroad, causing almost 5,000 people to be quarantined.

Almost 1,200 positive cases from the outbreak have been confirmed, according to Spain’s emergency health response coordinator, Fernando Simón, after Mallorca health authorities carried out mass testing on hundreds of students after the outbreak became clear. It is believed to have spread as hundreds of partying students gathered at a concert and street parties.

Officials have so far traced 5,126 travelers to Mallorca. More than 900 COVID-19 cases in eight regions across mainland Spain have been traced back to the outbreak.

Scores of infected teens are still on the island. Some are being kept in their hotel rooms, while others have been moved to a hotel being used by local authorities for isolation of those with mild symptoms or suspected cases.

Simón noted that the parents of the teens are probably around 45 and 55 years old and not all of that age group has received both doses of a COVID-19 vaccine, which could lead to community transmission.