Officers arrested a York City man and three teenage boys for allegedly committing two separate street robberies on Monday night, and the group is being looked at for possible involvement in other robberies as well, police said.

Steffen Tidwell, 18, of 129 N. Penn St., is charged with robbery, simple assault and related offenses. He remains in county prison on a total of $150,000 bail.

Three juvenile males are being charged as juveniles in the robberies, police said.

York City Police said that just before 6:30 p.m., Edwin Emminger III, 47, of Atlantic Avenue, was walking on Madison Avenue near the intersection of West Street when he saw shadows approaching him from behind.

When he turned, he was struck in the face with a BMX-style bicycle and fell to the ground, where the group of youths punched him in the face numerous times and robbed him of his wallet and cell phone, police said.

About 20 minutes later, a group of 10 to 15 youths -- two on bikes -- jumped David Myers, 46, of West Poplar Street, as he was standing near the intersection of West Philadelphia Street and Carlisle Avenue, police said. He was struck multiple times by the teens, who took his knapsack, iPod and other items, police said.

Officers tracked down the group and arrested Tidwell and three of the juveniles, police said.

Police are investigating the group's possible connection to other York City robberies.