An Uzbek immigrant has been charged by US prosecutors with causing the deaths of at least eight people in New York by mowing them down in a truck.
Sayfullo Saipov, 29, is also accused of providing material support and resources to the Islamic State (IS) group.
Sayfullo Saipov Photo: AFP / St Charles County Police Department
He was shot and injured by police at the scene of the attack and is receiving treatment in hospital.
Police say a second Uzbek man is wanted for questioning by investigators.
The FBI is seeking information on Mukhammadzoir Kadirov, 32.
Tuesday afternoon's attack saw a truck driven down a cycle lane in Lower Manhattan, hitting cyclists and pedestrians.
Six people died at the scene and two more in hospital. Twelve people were injured, nine of whom remain in hospital.
Police say Mr Saipov was inspired by IS.
New York Police's Deputy Commissioner John Miller said notes in Arabic claiming the attack on behalf of IS were recovered from the site of the attack.
Mr Miller said: "Based on the investigation overnight, it appears that Mr Saipov had been planning this for a number of weeks.
"He did this in the name of Isis [an alternative name for IS], and along with the other items recovered at the scene was some notes that further indicate that.
"He appears to have followed almost exactly to a 'T' the instructions that Isis has put out in its social media channels before, with instructions to their followers on how to carry out such an attack."
- BBC