Boston Marathon Bomber's Death Sentence Sparks Terrorist Threat Against U.S.

A terrorist leader has threatened "grave consequences" against the U.S. if it carries out a death sentence against surviving Boston Marathon bomber Dzhokhar Tsarnaev or any other Muslim prisoner.

According to Reuters, Al-Qaeda leader Ayman al-Zawahiri invoked Tsarnaev's name in an online video message.

“If the U.S. administration kills our brother the hero Dzhokhar Tsarnaev or any Muslim, (it) will bring America’s nationals the gravest consequences," he reportedly said.

Tsarnaev was convicted in the 2013 attack at the Boston Marathon finish line that killed three and injured more than 260. His brother and co-conspirator Tamerlan was killed in a police shootout during the manhunt that followed. For nearly a year, Tsarnaev has been held in America's highest-security prison in Florence, Colorado, after he was sentenced to death by lethal injection last June.

Zawahri came into power after Osama bin Laden's death in 2011 and regularly levels threats against nations through online propaganda videos such as this. The hope is to inspire action by followers, even as al-Qaeda's influence has largely diminished.

In the latest video, as described by the wire service, Zawahri is seen seated in front of green curtains as he urges followers to take westerners captive, targeting those who are part of the “Crusaders’ Campaign led by the United States."

Western countries "only understand the language of force," he reportedly said, urging al-Qaeda sympathizers to take these so-called "crusaders" hostage as bargaining chips in Muslim prisoners' release.

Zawahri (pictured above) is on the U.S. State Department's list of "most wanted terrorists."

>>> Full story from Reuters here.