Federal investigators are looking into at least 30 letters containing suspicious powder that were sent to banks in nine cities, including a number of Chase banks in New Jersey.

Police and hazmat crews have been called to investigate the notes, which were sent to nine banks in Ocean and Middlesex counties.

The notes allegedly contained white powder. According to the FBI, initial tests on the powder have come up negative for dangerous toxins.

The affected New Jersey banks are located in Lakewood, Toms River, Jamesburg, Monroe and North Brunswick. Letters were also mailed to Chase branches in Chicago, Cincinnati, Dallas, Denver, New York, Oklahoma City and Washington, according to law enforcement officials.