Boston Marathon bombing suspect Dzhokhar Tsarnaev has indicated he and his brother intended to detonate explosives in New York's Times Square, US police say.
New York Police Commissioner Ray Kelly said investigators learned of this plan while questioning the 19-year-old in his hospital bed in Boston.
He has been recovering from his wounds there since being captured on Friday night after an all-day manhunt that shut down much of Boston, Reuters reports. His brother Tamerlan Tsarnaev was shot and killed.
Mr Kelly said after authorities identified the brothers, the pair decided to drive to New York where they would set off bombs. The plan unraveled when they realised that a car they had hijacked on 18 April did not have enough petrol for the journey.
Earlier that day the FBI identified the ethnic Chechen brothers as suspects in the bombing at the finish line of the Boston Marathon that killed three people and injured 264 others, releasing pictures and video of them at the scene.
At the time, the men still had six explosive devices, including a pressure-cooker bomb of the type used at the marathon and six pipe bombs, Mr Kelly said.
When they stopped to fill up the vehicle, the driver of the car escaped. He alerted authorities and sparked a massive late-night car chase across the university town of Cambridge, where police said the brothers shot dead a Massachusetts Institute of Technology campus police officer.
The chase ended in an extended gun battle in suburban Watertown in which the suspects threw improvised explosives at police. The older suspect, 26-year-old Tamerlan Tsarnaev, was shot and died of his wounds.
Dzhokhar Tsarnaev was captured the next night in Watertown, hiding in a boat parked in the backyard of a house. He was formally charged on Monday in the hospital with crimes that could carry the death penalty.
Meanwhile, the suspects' father said he planned to travel to the United States from Russia to bury his older son.
His former wife, Zubeidat Tsarnaeva, angrily denied that her son had any role in the attack and criticised police for shooting her 26-year-old son while apprehending him.
Ms Tsarnaeva, who does not plan to accompany her former husband on his trip, has an outstanding arrest warrant in Massachusetts for failing to appear in court over shoplifting-related charges.