(WUSA) -- Monday night a woman was robbed at knifepoint when she went to deliver pizza at a home, which was unoccupied at the time of the robbery, say Spotsylvania County Sheriff's Office authorities.

The Pizza Hut delivery driver had arrived at the home in the 4600 block of Alliance Way shortly before 10:30 p.m. Monday when three black males approached her, say authorities. One male took out a knife and held the driver while the other males took cash from her. 

After receiving the cash, they fled on foot.

The suspects were described only as black males wearing all black and gray. 

Anyone with information is asked to call the Spotsylvania Sheriff's Office at 540-582-7115, 1-800-928-5822 or 1-540-582-5822. You may also text a tip: Text SEE911 to CRIMES (274637).