An Afghan immigrant to the United States has pleaded guilty to attempting to blow up New York city's subway system.
Najibullah Zazi was arrested in September last year. He pleaded guilty to conspiracy to use weapons of mass destruction, conspiracy to commit murder and providing material support to al-Qaeda.
Zazi, 25, changed his plea from one of not guilty and told a federal court he had been planning a "martyrdom operation", the BBC reports.
Zazi said he had agreed to carry out the attack as a protest against American military operations in his homeland, Afghanistan. He faces a sentence of life in prison without parole.
US Attorney General Eric Holder said the plot was one of the most serious threats to America since the September 11 terrorist attacks in 2001.
The US intelligence community has been under pressure ever since it failed to prevent an attack on a passenger jet bound for Detroit on Christmas Day, the BBC reports.