Boston blasts proved making bombs within 'everyone's reach', threatens Al Qaeda

Al Qaeda's affiliate in Yemen has said that the Boston Marathon blasts have revealed America's fragile security and proved that making bombs was within "everyone's reach".

Qassim al Rimi, the military chief of the group, urged Muslims in America to "carry on with this way" and defend their religion in an audio message posted online, reports Sky News.

In "A letter to the American people", Al Rimi said that the Boston events, and the poisoned letters sent to the White House, regardless of who is behind them, show that security is no longer under control, and that attacks have taken off and cannot be stopped.

The April 15 Boston blasts, which killed three people and wounded more than 260, are suspected to be carried out by two brothers - Dzhokhar (19) and Tamerlan Tsarnaev (26).

Tamerlan was killed in a shootout with police, while Dzhokhar was captured and taken into custody.

Al Rimi also said the killing of Al Qaeda's founder Osama bin Laden in May 2011 and top Yemeni-American cleric Anwar al-Awlaki in September 2011, had not ended the struggle.

In his message, he also he encouraged the Muslims in the US to carry on with this way, to be steadfast in their religion, carry out their obligations, defend their religion and follow in the footsteps of those who supported their religion.

Three letters laced with ricin have been discovered in recent weeks, one addressed to US President Barack Obama, one to Republican Senator Roger Wicker of Mississippi and a third to a justice of the peace in the same US state, Sadie Holland.

Russian officials told US congressman William Keating this week that the attacks could have been prevented if US authorities had acted on their warnings. Keating said he was provided with details of how US intelligence agents were warned in 2010 that Tamerlan was preparing to join a terrorist cell in the southern Russian region of Dagestan.