A Spanish national has been arrested at Sydney Airport after three indecent assaults on young children at McDonald’s restaurants across NSW, police say.

The 48-year-old was arrested near the international terminal about 4pm (AEDT) on Tuesday and taken into custody for questioning over the alleged attacks.

Police launched a manhunt after two boys reported being touched and kissed at separate McDonald’s restaurants in suburban Sydney within hours of each other on Saturday night, and a girl was kissed at a McDonald’s in Cowra, in NSW’s central west on Tuesday morning.

A man fitting the description of the offender in the Cowra incident was spotted on Monday at a fast food restaurant in Yass, where police believe he was intending another assault.

Staff recognised him and raised the alarm but the man fled before police arrived.A mother has reported that her four-year-old son was assaulted at a McDonald’s in Sydney’s inner-west Drummoyne on Saturday when she momentarily turned her back.