A 13-year-old was arrested Wednesday and police continue to looks for a second suspect in two armed robberies last week, city police announced.

The incidents were reported about 40 minutes apart at Welsh Park and the College Plaza shopping center in Rockville, city police said.

In the first incident, city police were called about 9:30 p.m. on July 31 for a report that several people had been robbed while playing basketball at Welsh Park, at Mannakee Street and Martins Lane.

The victims told officers that two suspects were seen going through the victims’ personal belongings, police said. When the suspects were confronted, a struggle ensued between one of the victims and a suspect. As they struggled, a second suspect pulled out a black pistol and pointed it at everyone, police said. The suspects fled with one of the victim's cell phones, according to the police statement.

City police were called again at 10:10 p.m. on July 31, for a report of a robbery of an employee at a business at the College Plaza shopping center, in the 15100 block of Frederick Road. The employee was taking out the trash when two suspects approached him, police said.

One of the suspects punched the victim in the face and the other pulled out a black pistol, police said. After obtaining cash and the victim's wallet, the suspects fled on foot.

After an investigation, police arrested a juvenile without incident on Wednesday. The juvenile was charged with two counts of armed robbery, seven counts of first-degree assault, two counts of theft under $1,000 and 11 counts of conspiracy to commit the listed charges, according to the police statement.

Police are investigating the identity of the second suspect, police said.

It was the second arrest of a juvenile charged in robberies last week, city police said. Another 13-year-old boy was arrested for a July 21 robbery at Elwood Smith Park, in which the suspects implied that they had a weapon.

In that unrelated robbery, which was reported at 9:35 p.m. on July 21, police said the victim was walking from the Rockville Metro station to a friend's house.

Four juvenile males on bikes approached the victim at the entrance to Elwood Smith Park, near Mount Vernon Place and implied, but did not show, a weapon, police said. The suspect or suspects took the victim's wallet and cell phone.

The 13-year-old was arrested without incident Thursday at his home, police said. He was charged with one count of strong arm robbery, one count of theft under $1,000, one count of using a credit card belonging to another and three counts of conspiracy to commit the listed charges, according to police.

An investigation is continuing to identify the other suspects.

Anyone with information about these incidents or the individuals involved is asked to call Rockville City Police Criminal Investigations Unit at 240-314-8938.

This post was updated at 2:40 p.m. on Aug. 7.