Police in Boston investigating the scene of yesterday's twin bomb attacks,have found pieces of nylon which they say,could be from the bag used to conceal one or both of the devices.

The blast close to the finishing line of the Boston marathon, killed three people and injured more than 170. Investigators say, they are yet to uncover the motive or identify a suspect and there have been no claims of responsibility so far for the blasts.

FBI Special Agent Richard DesLauriers told a news conference that pieces of nylon have been recovered from the scene, along with fragments of ball bearings and nails that were possibly contained in a pressure-cooker device.

Authorities said, the devices used in the twin blasts were similar to those used against American troops in Iraq and Afghanistan.
President Barack Obama will travel to Boston tomorrow for a memorial.