More than 200 Dutch teenagers have tested positive for coronavirus after coming back from post-exam celebrations in resorts such as Mallorca, the RIVM has confirmed.

The public health agency is concerned that travel to other European countries could trigger a new wave of infections, as happened last year when a surge in cases in Spain and the south of France rippled out to the Netherlands in July.

In its latest weekly bulletin the RIVM reported 191 cases in people who had travelled to Spain in the previous two weeks and 134 in visitors to Portugal. The cases represent 3.6% of all positive tests in the last week.

Portugal, the Balearic Islands and the Canary Islands are currently considered yellow risk by the foreign ministry, meaning travellers are not required to take a coronavirus test before coming home and do not have to quarantine when they return.

The RIVM said infections were declining less slowly in the 15 to 19 age group, particularly in and around Amsterdam. ‘We are seeing in Amsterdam that many exam students are coming back with infections,’ a spokesman told the Parool. ‘These are mainly holidaymakers from Mallorca.’

Coronavirus infections have been falling by more than 30% a week since the start of June, but in the Amsterdam-Amstelland and Gooi en Vechtstreek health board (GGD) regions the rate has started to creep back up in recent days.

Infections have been detected at five schools: the Amsterdams Lyceum, the Sint Nicolaas Lyceum, the Vierde Gymnasium, the Berlage Lyceum and the IVKO. The schools have taken extra precautions including asking all students to test themselves the night before sitting an exam.

The RIVM is concerned about the risk of tourists catching the Delta variant, which has sparked a rise in cases in the UK, especially as Mallorca is a popular destination for British youngsters.

The agency has urged people returning from trips to Spain and Portugal to book a PCR test when they come home even if they have no symptoms.

Student Arte Weggemans told the Parool that one of his friends tested positive after falling ill shortly after coming back from Mallorca.

‘Maybe it was naive, but I didn’t expect this,’ said the 17-year-old, who has had a negative test result. ‘We all took a negative PCR test before we left, so we must have become infected in Mallorca.’