The woman was pushed to the ground around 1.45 pm near the Schelpenkade and then raped, the police reported.
The victim called for help and her attacker fled. Witnesses saw the man run away in the direction of Drie Octoberstraat where he had parked his bicycle. The man got on his bicycle and cycled away through Drie Octoberstraat in the direction of Schelpenkade.
Police are asking anyone with more information to come forward.