The FBI has released photos and video of two suspects in the Boston Marathon bombings and is asking for the public’s help in identifying the men.
FBI Agent Richard DesLauriers says the images, depicting one man with a black baseball cap and one with a white cap, came from surveillance cameras near the explosion sites shortly before the blasts.
“We consider them to be armed and extremely dangerous,” Mr DesLauriers said, asking the public not to approach the men.
He said there is no additional danger that the FBI knows of now.
Monday’s blasts killed three and injured more than 180.
The images were released hours after President Barack Obama attended an interfaith service in Boston to remember the victims, including an eight-year-old boy.
The FBI’s website crashed within moments of the images being released tonight.
They show two young-looking men wearing baseball caps, wearing jackets and carrying backpacks along the race route and weaving through the crowd.
“Each piece moves us toward justice,” Mr DesLauriers said of the latest information to emerge.
He said one suspect is believed to have planted the explosive devices near the finishing line of the world-famous marathon.
The authorities had warned people not to expect the case to be cracked quickly as they looked through a vast response to their plea for photos and video from the blast scene.
The images came out hours after Mr Obama promised a grieving city to hunt down whoever was responsible.
At the interfaith service honouring the victims, the president called the perpetrators of the attack “these small, stunted individuals who would destroy instead of build”.
The blasts killed eight-year-old Martin Richard, 29-year-old Krystle Campbell and Lu Lingzi, a graduate student from China. Seven victims remained in critical condition.
The bombs were crudely fashioned from ordinary kitchen pressure cookers packed with explosives, nails and ball bearings, investigators said. They suspect the devices were then hidden in duffel bags and left on the ground.
They exploded within 15 seconds of each other near the finishing line at a time when thousands of runners were pouring in.
Several media outlets had reported that a suspect had been identified from surveillance video taken at a Lord & Taylor department store between the sites of the bomb blasts.