A Muslim-American man pleaded guilty Friday to his role in a plot to use remote-controlled model planes packed with explosives to blow up the Pentagon and U.S. Capitol.

Rezwan Ferdaus, of Ashland, pleaded guilty to attempting to provide material support to terrorists and attempting to damage and destroy federal buildings by means of an explosive.

The 26-year-old was arrested last year after federal employees posing as Al Qaeda members delivered materials he requested, including grenades, machine guns and plastic explosives.

Under a plea agreement, federal prosecutors agreed to drop four other charges. Prosecutors and Ferdaus' lawyers also agreed to request a 17-year sentence on charges that carry a combined maximum of 35 years in prison.

Ferdaus grew up in Massachusetts and has a physics degree from Boston's Northeastern University.

His mother sobbed uncontrollably after Ferdaus was led away. She had to be helped by Ferdaus' brother.