SEATTLE — Federal agents are warning 11 medical marijuana dispensaries in the Seattle area to shut down.

The Drug Enforcement Administration sent letters to the dispensary operators and landlords, saying that the businesses are at risk of federal prosecution because they are located within 1,000 feet of a school, park or other sensitive location.

Seattle DEA spokeswoman Jodie Underwood says the letters are identical to ones mailed last summer to more than two dozen dispensaries in the area.

She declined to identify which dispensaries received the new round of letters, which were sent Monday. They warn the operations to shut down within 30 days.