The men were hanged over the past week, the hard-line daily Qods wrote.
Gholam-Hossein Esmaeili, Mashads Chief Prosecutor, said that the judiciary was acting decisively against those creating instability.
He added that the 15 individuals had been hanged for drug trafficking.
Iranian authorities routinely execute dissidents on bogus charges such as armed robbery and drug smuggling.
Mashad was the scene of a major anti-government protest last week, with local residents attacking agents of Irans State Security Forces (SSF) who were attempting to detain a woman for mal-veiling. During the clashes, the SSF fired teargas and attacked angry protestors with batons. A nationwide clampdown mainly targeting women for mal-veiling began in mid-April.
