The city of Portland has issued a "yellow zone" parking ban for Monday night into Tuesday morning. The ban will take effect at 10 p.m. Monday and last until 6 a.m. Tuesday. The yellow zone includes the downtown district bounded by Cumberland Avenue, Franklin Street, Commercial Street and State Street.Vehicles left on city streets within the zone can be towed at the owner's expense.Portland police said Monday morning that crews towed more than 100 vehicles during the citywide parking ban that was in effect from 10 p.m. Sunday to 6 a.m. Monday. Those vehicles were taken to the impound lot at the Ocean Gateway Marine Terminal next to the Maine State Pier at 40 Commercial Street. The impound lot is open until 7 p.m. daily. Unclaimed vehicles will eventually be taken to individual towing company impound lots.Drivers whose vehicles were towed will need to bring cash or credit cards to claim their vehicles. Only VISA, MasterCard or Discover Card are accepted. The tow fee is $100. There is also a $35 impound fee and a $35 ticket for a total of $170. Any unpaid tickets must also be paid.During the first parking ban of the season in Portland, in November, police said they did not tow any vehicles, but they did issue 440 tickets.