Fairfax County police believe a string of four armed robberies that occurred in the Franconia and Springfield areas over the course of an hour late Thursday night are connected.

In each instance, three male suspects approached a victim who was alone, police said. They said the men were armed with a pistol.

The first case occurred about 10:15 p.m. when three suspects wearing ski masks robbed a 27-year-old woman as she exited a building in the 6900 block of Kingstowne Village Parkway, police said.

About 15 minutes later, a trio robbed a 22-year-old woman as she exited her car in the 5900 block of Norham Drive, police said. After demanding the victim’s money, one of the men struck her with a gun before fleeing.

At 11 p.m., the men robbed a 20-year-old man as he was pulling into his driveway in the 6300 block of Dana Avenue. The robbers, who were wearing black, hooded sweatshirts, ordered the man out of his car. After the robbers demanded and received the man’s money and belongings, one punched the victim in the face. All three robbers fled in a black Toyota Camry.

In the last incident, around 11:30 p.m., the trio robbed a 25-year-old man in the 6500 block of Quander Road. The men fled without injuring the victim.

Anyone with information should contact Fairfax Crime Solvers at 1-866-411-TIPS/8477. They can also be reached online at http://www.fairfaxcrimesolvers.org or text “TIP187,” plus your message, to 274637.