Urbandale police are asking residents to be on alert after pop bottle bombs have caused some damage within the city.
Police say two of the homemade explosive devices were placed inside mailboxes in the western part of Urbandale. Both bombs caused property damage.
Destroying a mailbox is a federal felony and punishable by a fine and a prison term up to three years.
Police are asking the public to keep an eye out for suspicious activity. If you need to report something suspicious or have information on the pop bottle bombs you can contact U.S. Postal Inspectors at 1-877-876-2455.