Hidden behind glasses, a mustache, a wig or a mask, someone or several people have recently been pilfering pills from pharmacies around the Lowcountry.

Law enforcement agencies are investigating a series of pharmacy robberies that have occurred in the past week. Summerville police are looking into two of them, one last week and another this week.

Mount Pleasant saw one on Monday. In all three, the robbers stole a form of oxycodone.

Summerville detectives have been in contact with investigators from Mount Pleasant, but Summerville’s Capt. Jon Rogers said it’s too early to tell if all three are connected.

Based on a Post and Courier review of area police reports, there were at least 13 pharmacy robberies in 2012, up from about four in 2011.

Early Tuesday, a CVS pharmacy at 301 N. Main St., Summerville, was robbed. At 5:52 a.m., a man with his face covered and carrying a hammer entered the store, jumped the pharmacy counter and demanded Oxycontin, police said. The staff handed him an undetermined amount of medication.

No customers were in the business at the time of the robbery and no employees were injured, police said.

Summerville police also are investigating a Thursday robbery at a Walgreens on Trolley Road.

In that robbery, a man passed a note to an employee at the pharmacy asking for all of their Oxycontin, police said.

That man was white and was wearing a baseball cap, glasses, a black wig and a fake mustache, according to the police report.

On Monday, a masked man wearing a camouflage jacket and blue latex gloves robbed a Mount Pleasant pharmacy. That robbery led to the lockdown of a nearby school.

The man robbed the East Cooper Family Pharmacy at 913 Bowman Road at around 9:45 a.m., according to an incident report.

He reportedly was armed with a handgun and stole medication including five bottles of oxycodone and two bottles of hydromorphone, according to the report.

Several police officers searched for the suspect near the area. James B. Edwards Elementary School on Von Kolnitz Drive was locked down shortly after police responded to the incident, according to Charleston County School District spokesman Jason Sakran.

When police arrived at the pharmacy, a female employee was described by officers as upset and crying, according to the report.

The robber went in and out of the pharmacy through the walk-up door on the north side of the building that faces Bowman Road.

Police said they don’t have a photo of the suspect to release at this time.

Reach Natalie Caula at 937-5594 or Twitter.com/ncaula.