ISIS: Yemen Attack 'Glimpse of an Upcoming Flood'

A Yemeni branch of the Islamic State is claiming responsibility for a quadruple suicide bombing in Yemen that left at least 137 people dead and more than 300 wounded.

The bombings took place during midday prayers Friday at two mosques controlled by Shiite Houthi rebels in the capital city of Sana'a.

One witness said one of the terrorists walked inside the mosque and detonated a bomb. That explosion was soon followed by another.

"I fell on the ground and when I regained consciousness I found myself lying in a lake of blood," one survivor, Ahmed al-Gabri, told The Associated Press.

In a statement posted online Friday, a  group calling itself the media office of ISIS's "Sanaa Province" warned Friday's devastation was just a "glimpse of an upcoming flood, God willing."

"We swear to avenge the blood of Muslims and the toppling of houses of God," the group vowed.

"The soldiers of the Islamic State ... will not rest until we have uprooted (the Houthis), repelled their aggression, and cut off the arm of the Iranian project in Yemen," it said, referring to claims that Iran is backing the rebels.

According to investigators, the group's claims haven't yet been confirmed.