The Dutch public prosecution department has refused to comment on claims that members of an IS cell spent time at a refugee centre in Nijmegen, broadcaster NOS said on Tuesday.

French newspaper Le Monde reported last week that a cell of 20 IS sleepers were living in Nijmegen and Dusseldorf in Germany and were ready to commit atrocities when ordered to do so. The paper bases its claim on evidence from Saleh A, a former jihadi who turned himself over to French police in February.

The Netherlands and Germany were warned about the claims, Le Monde said.

Three Syrian nationals, said to be members of the cell, were arrested in Dusseldorf last week. No one has been arrested in the Netherlands and the public prosecution department says it cannot comment on ‘any eventual ongoing investigations’.

Nijmegen was home to the biggest Dutch refugee camp until it was closed last month. It is not clear if the Le Monde claims refer to this camp, the NRC said.

The Dutch counter-terrorism tsar Dick Schoof said in March there are signs Islamic militants have been attempting to abuse the refugee system to enter Europe.