Police in Rotterdam have arrested four men – three from the Netherlands and one Swedish national – on suspicion of involvement in terrorist activities. They were picked up after a tip from the Swedish police about the 29-year-old Swede.

The three Dutch men come from Vlaardingen, Delft and Gouda. They were arrested in a car in the centre of Rotterdam shortly after the Swede arrived in the Netherlands on Sunday.

A public prosecution department spokesman said there is no evidence the four were planning an attack and no explosives or weapons were found at their homes.

‘However, the police and the justice ministry take no risks whatsoever when it comes to preventing terrorist attacks,’ the spokesman said.