President Barack Obama has ordered flags at the White House and all government buildings to be flown at half-mast in honour of the Boston Marathon explosion victims.
Obama signed a proclamation making the order Tuesday morning, calling it a "mark of respect for the victims of the senseless acts of violence". He ordered flags to remain lowered until sunset on Saturday.
New photos of the suspects identified by officials as Dzhokar A. Tsarnaev, 19 and Tamerlan Tsarnaev, 26 have been released.
The FBI has released pictures and video of two suspects in the Boston Marathon bombing, seeking the public's help.
President Obama attended a memorial service in Boston today, paying tribute to the victims of Monday's terrorist attack.