A man with an Uzi submachine gun robbed six West Philadelphia businesses this week - the latest last night - during which he threatened employees and patrons with the fearsome weapon, police said yesterday.

In three of the robberies, an accomplice wielded a 9mm handgun. In all five, the robbers fled on black BMX bicycles, police said. Detectives are concerned that the guns, coupled with the apparent youth of the robbers, could lead to a deadly confrontation.

In one of the robberies, at a neighborhood bar, patrons chased a suspect on foot, and the bar owner followed the gunman in his car before losing him in some of the area's narrow streets.

Lt. John Walker of Southwest Detectives said the firearm on automatic mode can quickly let off a lot of rounds.

"The way that gun sprays, people are going to be hit," he said.

In last night's job, a masked man robbed Neet's Lounge, a bar at 5127 Market St., around 8:30 p.m., Walker said.

The robber was armed with an Uzi-like firearm, took money from the register and fled on a bicycle, Walker said.

The string of robberies began Tuesday night at the State Store at 51st Street and Lancaster Avenue. In addition, the robbers hit another State Store, at 46th Street and Lancaster; two bars, at 50th and Market Streets and at 52d Street and Wyalusing Avenue; and a market in the 5100 block of Haverford Avenue.

Police believe the robbers, said to be 18-20 years old, live in the area and will keep at it.

"They're not getting much money," Walker said. "That's why we think this is going to continue."