Dutch military police said on Sunday they had arrested a married couple who left a hotel where they were in quarantine after testing positive for Covid-19, and were attempting to flee the country.
They were arrested "in an airplane that was about to depart," the police said in a statement.
It was unclear whether they had tested positive for the new Omicron coronavirus variant.
Amsterdam newspaper Het Parool reported that the couple, a Spanish man and Portuguese woman, were trying to fly to Spain.
Dozens of passengers who tested positive for Covid-19 after arriving on two flights from South Africa on Friday are being kept in quarantine at a hotel near Amsterdam's Schiphol airport.
The statement said the pair, whose names and nationalities were not released, had been turned over to health authorities.
In all, 61 of the more than 600 passengers on the flights from Johannesburg and Cape Town tested positive for Covid-19. Most are quarantining at the hotel, though some Dutch residents were allowed to quarantine at home.
Dutch health authorities said earlier on Sunday that at least 13 of the 61 are infected with the newly identified Omicron variant of the virus.
The police did not release further details of the couple's medical status.