A couple was arrested in the Netherlands after escaping hotel quarantine, Dutch police said.
They added that the arrests took place on a plane that was about to take off for Spain.
The couple, a man from Spain and a woman from Portugal, were handed over to the health authorities, police told Euronews.
One of the people who escaped was positive for COVID-19; they are now back in quarantine, police said. They had recently returned from South Africa.
It comes after the Dutch public health authority said on Sunday that 13 people who arrived on flights from South Africa had so far tested positive for a new coronavirus variant, Omicron.
A total of 61 people arriving from the area had tested positive for the virus but police did not immediately specify if the couple that escaped from quarantine had arrived from there.
Many countries have imposed travel restrictions over the new coronavirus variant that has been labelled by the World Health Organization as a "variant of concern".
The UN health agency said that preliminary evidence suggests an increased risk of infection.