BOSTON: An American supporter of al Qaeda pleaded guilty on Friday to plotting to bomb the Pentagon and US Capitol using remote-controlled model planes laden with explosives.

Rezwan Ferdaus, 26, admitted to attempting to provide material support to terrorists and attempting to damage and destroy federal buildings by means of an explosive.

Federal Judge Richard Stearns accepted his plea and set a final sentencing hearing for November 1.

According to his agreement with US prosecutors, Ferdaus will be sentenced to 17 years in prison, followed by 10 years of probation. In return for his guilty plea, the government agreed to drop four other charges against him.

Ferdaus kept quiet during the one-hour hearing. Several relatives, including his parents, attended the session.

Authorities described Ferdaus as an unmarried physics graduate from Boston's Northeastern University. The al Qaeda supporter reportedly committed himself to “violent jihad” early last year.

He was arrested in September as part of a sting operation in which FBI agents posed as members of al Qaeda.

During the investigation, Ferdaus described to undercover agents his step-by-step plan of attack, Assistant District Attorney Stephanie Siegmann said.

The prosecutor said Ferdaus told the agents he planned to use aircraft filled with grenades and mobile phone-activated explosives to bring about the “downfall of this disgusting place,” the United States.

Ferdaus was also accused of modifying mobile phones for use as switches in bombs to kill US soldiers in Iraq and to having given the devices to FBI agents “he believed were members of or recruiters for al Qaeda.”

A white Playboy bunny graced the tail end of one of three model planes filled with C4 plastic explosives, slated to hit the Pentagon or blow the Capitol's dome “to smithereens,” he was quoted as saying in court files.

According to the original complaint, when told - falsely - that one of his phones had been part of a bomb that killed three soldiers, Ferdaus said: “That was exactly what I wanted.”