The first one was on Sunday at around 9am. A woman reported that she was walking along Terry Street when the suspect approached her, put his arms around her and tried to kiss her. She pushed him off and he ran away.
The second incident was on Monday on Temple Street around 1.30pm. The man spoke to a woman in passing then followed her and touched her bottom. He then ran off towards Bridlington Avenue.
Neither women were injured and the man has been described as dark skinned, skinny, in his mid 20s to mid 30s, with short brown hair and around six feet tall.
A spokerman for Humberside Police said: "We want to reassure the wider public that we are increasing patrols in the area and are appealing for anyone who may have seen this man, or who has any information, to contact us."