A man has been arrested after a number of Auckland women were allegedly attacked in the space of an hour-and-a-half has been charged with indecent assault.

Police on Saturday said as many as nine women were assaulted "at various locations in central Auckland between around 1:30pm and 2:50pm", but now say they have received 12 complaints.

"Further charges will be filed," police said on Sunday morning. He will appear in Auckland District Court on Monday.

"Police urge anyone with any information, including anyone who saw anything concerning in central Auckland... to contact police straight away on 09 302 6557 or Crimestoppers anonymously on 0800 555 111," a police spokesperson said on Saturday.