A day after a bombing injured 29 people in a Manhattan neighborhood, police are scouring the area for clues about who was responsible for the explosion and why it happened. “We know it was a very serious incident, but we have a lot more work to do to be able to say what kind of motivation was behind this,” New York Mayor Bill de Blasio told reporters Sunday. “Was it a political motivation? Was it a personal motivation?

We do not know that yet.” A few blocks away from the blast site, investigators found one possible clue: a pressure cooker, with dark-colored wiring sticking out, connected by silver duct tape to what appears to be a cellphone, officials said. It’s still unclear whether that suspicious device has any connection to Saturday’s explosion, which shook New York City’s Chelsea neighborhood and sent panicked people scrambling for cover. READ MORE