Police are stepping up the manhunt for an Uzi-wielding, bicycle-riding bandit who defiantly struck again last night in West Philadelphia just hours after authorities issued an alert for him and an accomplice.

Police say they fear someone will get wounded or killed if they are not stopped.

No shots were fired and no was injured in the latest stickup - the sixth in the same neighborhood since Tuesday night - at Neet's Lounge at 51st and Market Streets.

In three of the robberies, an accomplice wielded a 9mm handgun. The masked gunman flees on on black BMX bicycles, as does the accomplice when he joins in, police said.

Detectives are concerned that the robber's fire power, coupled with their apparent youth, could lead to a deadly confrontation.

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, the masked man walked into Neet's Lounge 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.