Fayetteville, N.C. — Fayetteville police are investigating whether a series of robberies targeting delivery drivers in recent months might be linked.

A weapon – either a knife or gun – was reportedly involved in each of the robberies, a Fayetteville police spokesman said.

The first robbery, involving a Domino's driver, happened June 28 at 2:11 a.m. in the 5300 block of Ramsey Street.

The others happened this month – two involving Papa John's drivers on Aug. 8 at 9:48 p.m. in the 5400 block of Wichita Drive and at 10:52 p.m. in the 2900 block of Raeford Road.

The next day, a driver for a Chinese restaurant was robbed at 9:50 p.m. in the 700 block of Perley Street.

The driver told WRAL News on Monday that he went to what appeared to be a vacant house and that a man in the driveway approached him and put a knife to his throat before taking $30 in cash, his cellphone and the food.

The final robbery, which involved a Domino's driver, happened Aug. 10 at 9:39 p.m. in the 700 block of Commerce Street.

Anyone with information that could assist police is asked to contact the Fayetteville Police Department at 910-433-1856 or Crime Stoppers at 910-483- 8477.

Police, meanwhile, are offering these tips for restaurant employees in light of the recent robberies:

- Record a name and telephone number of the customer and full delivery information (e.g., address, location, description of property).

- Confirm the order to eliminate suspicious or false orders. On suspicious calls, have the caller repeat the address on a confirmation call. If it is not exact, do not deliver.

- Make sure delivery drivers don't carry excessive cash and publicize it. Do not accept bills larger than $20, which eliminates drivers carrying excess money. Encourage drivers to leave personal funds at home.

- Limit the number of deliveries that drivers make on one trip. Excessive deliveries on one trip might mean that a driver has cash that can make him or her a target.

- Make sure each driver has a cellphone to call police in case of an emergency.

- Plan routes before leaving the store, and make sure drivers know where they’re going.

- Avoid known trouble areas. Do not deliver to intersections or the front or rear of buildings. Have an exact address or apartment number.

- Upon arrival, if the area does not look "right," leave immediately. Use common sense and obey instincts.