Police on Long Island are looking for an armed robber who was wearing a surgical mask and gloves when he stole about a dozen bottles of painkillers from a pharmacy Monday morning.

The gunman walked into Harry's Pharmacy at 333 South Broadway in Hicksville at about 9:50 a.m., wearing a bright yellow jacket, dark baseball cap, white surgical mask and gloves, police said.

Carrying a plastic bin, he walked straight past the cash register to the area behind the pharmacy counter where oxycodone was stored, the business owner told NBC 4 New York.

The robber demanded that an employee open the cabinet, then loaded 10 to 15 bottles in his container before running out of the store, fleeing northbound on Broadway toward Roosevelt Street.

The owner said she believes the man is a customer at the pharmacy because he knew exactly where the drugs were stored.

She said she now plans to hire a security guard.

The suspect is believed to be in his mid- to late 30s. Anyone with information is asked to contact Nassau County Crime Stoppers at 800-244-TIPS.