The county prosecutor is doing the investigations after two women said they were victimized while the city celebrated St. Patrick's Day.
One woman says she was attacked on Friday night, and the other on Saturday afternoon, the day of the parade.
Police are looking at cameras to see if anything was caught on tape.
Mayor Dawn Zimmer released the following statement:
The City of Hoboken confirms that there were two allegations of sexual assault reported over the weekend: one on Friday, March 4th, and another on Saturday, March 5th. These matters have been referred to the Hudson County Prosecutor's Office for investigation, and the City will continue its communication with the Prosecutor's office to monitor developments in these cases.
"These allegations are extremely serious," said Mayor Dawn Zimmer. "My Administration will fully review all of the activities that occurred on Hoboken's St. Patrick's Day so we can properly evaluate all of the facts and make fully informed decisions going forward."
Over the last two years, the City has worked to dramatically increase Police presence in an effort to ensure the safety of residents and visitors.
"I want to assure the public that my Administration is in the process of conducting a complete review of this year's event and will be making recommendations to the City Council as to how to move forward next year," added Mayor Zimmer.