Fairfax County police said yesterday that there has been a series of armed robberies of pedestrians in neighborhoods near the Franconia-Springfield Metro station during the last five weeks, including three Monday night in the Kingstowne area.

The armed robberies in Kingstowne bear some resemblance to four others since Sept. 21, and police are trying to determine if they are related.

"We don't know that they're all linked," Fairfax County police spokeswoman Mary Mulrenan said. "We're not saying it's the same person, but there's been an increase in armed robberies of pedestrians in that area. People might want to take precautions."

Officers planned to fan out last night at the Springfield-Franconia Station to urge people to be alert.

Monday's holdups occurred just blocks apart, starting with the robbery of a 41-year-old man at 9:50 p.m. as he walked with his wife on a footpath in Kingstowne that connects Rockleigh Way and Crestleigh Way.

Investigators said an armed suspect grabbed the victim by the jacket, causing him to drop his belongings. His wife managed to run off and called the police. The victim was able to slip out of his jacket and run home. When police arrived at the crime scene, the items the victim had dropped were gone.

The suspect in that case is described as a white male in his twenties, about 5 feet 11 inches tall and 170 pounds, with brown hair and eyes. He was wearing a dark-colored peacoat, tan pants and a multicolored knit hat.

Police were called back to Kingstowne at 10 p.m. after a 38-year-old man was robbed at gunpoint as he walked east on Crestleigh Way near Crestleigh Circle.

The victim told police he was approached from behind by a man who told him to walk to a path in the 6500 block of Brookleigh Way. The robber demanded the victim's wallet and briefcase and then fled south behind some townhouses, police said.

The victim described the suspect to police as a black male in his twenties, about 5 feet 8 inches tall and 160 pounds. He was wearing a dark down jacket, baggy dark pants and a scarf and hat.

Police said the third robbery occurred at 11:30 p.m. while a 34-year-old Springfield man was delivering pizza in the 6300 block of Hillary Court. Police said the deliveryman was grabbed by the arm and taken behind a house by a man, who then demanded his wallet.

The suspect was described as black, in his twenties, about 5 feet 8 inches tall and 160 pounds, with his hair in cornrows.

Police said three of the previous victims were robbed in the 7100 block of Barry Road as they walked from the Metro. A fourth person was robbed on Windham Avenue.