The spring session of Dukes County superior court began Monday with a grand jury indicting three men on drug charges stemming from a September incident in Oak Bluffs.

Mike G. Jean-Francois, 26, of Middleboro, Brandon F. Merkman, 32, of Sagamore and Quentin A. Phillip, 28, of Boston, were all indicted on one count of trafficking oxycodone, 18 to 36 grams and one account of conspiracy to violate the controlled substance act.

Mr. Phillip, Mr. Merkman and Mr. Jean-Francois were arrested Sept. 3 in Oak Bluffs.

According to a police report filed with the district court, police were monitoring a seized cell phone that they lawfully possessed when a male named Mike allegedly offered to sell more than 200 oxycodone pills.

The investigation led police to Fat Ronnie’s restaurant on Circuit avenue, where the defendents were spotted, the police report said. Officers allegedly observed a plastic prescription bottle with no markings inside a hat where the men had been sitting.

According to the police report, officers discovered 268 30-milligram Percocet pills inside the prescription bottle, which had no label. Police said they found another 23 Percocet pills in Mr. Phillip’s pockets.

The Hon. Tina S. Page, an associate justice of the superior court, is presiding over the superior court session, which runs for the rest of the month in the Edgartown courthouse. A mix of civil and criminal cases will be heard.