Tampa police are investigating a string of robberies targeting food delivery drivers.

According to the Tampa Police Department, the suspects robbed 13 delivery drivers over the last four months. Two of the victims worked for Asian restaurants, while the other 11 delivered pizza.

Police said they do not believe all the robberies are related, and that it appears as though multiple suspects are using the same modus operandi to rob delivery drivers in different parts of the city.

Officials said the suspects are mainly black men who vary in age, height and overall description. The majority of the robberies took place in areas described by police as "problematic."

Police said crime prevention teams are visiting with restaurant owners to make them aware of the crime trend and providing them with safety tips and checklists of suspicious signs to look out for when taking delivery orders.