New York - A federal jury on Tuesday found a Bosnian-born United States citizen guilty of planning a co-ordinated suicide bomb attack on New York City subways in 2009 at the behest of senior al-Qaeda operatives.

Adis Medunjanin, 28, faces a maximum sentence of life in prison following his conviction on all charges, including conspiring to carry out a suicide attack on American soil, receiving military training from al-Qaeda and plotting to kill US soldiers fighting in Afghanistan.

Medunjanin's accused co-conspirator Najibullah Zazi was arrested in September 2009, just days before Medunjanin and a third member of the plot, Zarein Ahmedzay, were prepared to carry out what US Attorney General Eric Holder has called “one of the most serious terrorist threats” to the United States since the attacks of September 11, 2001.

Prosecutors had argued Medunjanin was “ready and willing to sacrifice himself to kill” at the command of al-Qaeda, saying he committed to carrying out a suicide attack on American soil, a mission given to him by al-Qaeda operatives he met in Pakistan.

“What he was willing to do was to strap a suicide bomb to himself, walk into a New York City subway and blow it up,” Assistant US Attorney Berit Berger said in closing arguments last week at the US District Court in Brooklyn, New York.

Medunjanin, a US citizen born in Bosnia, was accused as the third member of a plot to bomb the subways in 2009. His high school friends Ahmedzay, 27, and Zazi, 27, both pleaded guilty to planning the attacks with him and are co-operating with the government, awaiting sentencing.

The jury began deliberations on Monday to decide whether to convict Medunjanin of the nine counts against him.

The judge allowed the jurors to remain anonymous for their safety. - Reuters