A Topsham tanning salon was robbed at gunpoint Tuesday evening, police said.

A man described as between 6 feet and 6 feet, 2 inches tall, wearing a long, hooded sweatshirt and with his face covered entered Sun Tan City in the Topsham Fair Mall about 8:32 p.m., displayed what appeared to be a semiautomatic handgun and demanded money.

He fled with an unspecified amount of cash. Police tried to track the suspect with a police dog but were unsuccessful.

The statement by Topsham Police made no mention of whether the robbery is believed to be connected to a string of 10 hold-ups throughout Greater Portland since March 20.

Topsham Police Detective Mark LaFountain said he has communicated with an FBI task force working with local police to solve the string of robberies, and is operating under the presumption that the Sun Tan City robbery is connected to the others until facts prove otherwise.

LaFountain said he spent Wednesday running down leads and looking for surveillance footage that might prove helpful. There was no footage available from the tanning salon, and LaFountain said he does not expect to release any video from the robbery at this time.

Each of the previous robberies involved a masked man dressed head to toe in dark, heavy clothes and wearing gloves. In each case, the robber displayed a handgun, demanded cash, and fled on foot. Police believe the robber then got into a vehicle nearby and drove away from the crime scenes.

In response to that string of robberies, officers have stepped up patrols near small businesses and advised store owners not to keep large amounts of cash on hand. They also have asked small-business owners to make sure their surveillance systems are functioning.

The previous armed robberies, most of which have taken place around 8 p.m., include the Riverton Gas Station, 1585 Forest Ave., in Portland, March 20; the Lil’ Mart, 251 Route 1, Falmouth, March 21; Good Things Variety, 113 Saco St., Westbrook, March 22; Irving Express Mart, 174 Main St., Cumberland, March 22; Daily Grind, 840 Main St., Westbrook, March 24; China Taste, 1223 Washington Ave., Portland, March 25; Subway, 390 Bridgton Road, Westbrook, March 26; Aroma Joe’s, 443 Western Ave., South Portland, March 27; and the Old China Eatery, 5 Ocean Park Road, Old Orchard Beach, March 29. The Old Orchard Beach robbery occurred at 3:38 p.m.

The rash of crimes is abnormal in Maine.

In 2016, there were 59 robberies in Maine that included the use of a firearm. There were 266 robberies in Maine overall that year, the most recent for which federal crime data is available.

Cumberland County had 94 robberies overall in 2016, or about one every four days, according to the data. There is no county breakdown of robberies with and without a firearm.

The latest string of crimes far outstrips the county’s historical rate, with the recent ones now representing more than 10 percent of the county’s annual total in just over a week.

Matt Byrne can be contacted at:

mbyrne@pressherald.com