Portland police are investigating an armed robbery that occurred in the Old Port over the weekend, one of a series of recent robberies in the city.

Police say two men confronted a man at 261 Commercial St., threatened him with a handgun and stole his wallet. The robbery occurred just before 10 p.m. Saturday. They took less than $100, police said.

The two men were described only as white, between 5 feet, 8 inches and 5 feet, 10 inches tall, clean-shaven with dark clothing.

Nobody was injured in the incident, which occurred near the end of Center Street.

On Saturday, at 5:30 p.m., a man tried to run off with a woman’s purse as she was lying on the Eastern Promenade across from Cutter Street. He gave up and ran toward Wilson Street, police said.

The two cases are in addition to a taxi holdup Sunday morning that led to the arrest of two men on robbery charges and a separate charge of stealing a cab driver’s money as he tried to make change.

“This weekend we saw a drastic increase in the number of robberies,” said Lt. Tony Ward, head of detectives for the Portland police.