The attacks, which killed at least 137 and injured more than 300, came during Friday prayers at Shiite mosques in Sanaa, Yemen‘s capital city.
The explosions occurred in rapid succession at the Badr mosque and at a second Sanaa mosque on Friday, the most important day of the Muslim week, according to the Reuters news service.
A third mosque targeted in Sadaa province was spared when a bomb intended for that building went off prematurely, Reuters said.
Bombers wearing explosive suicide belts carried out the attacks.
Sanaa is controlled by the Iran-backed Houthi, a Shiite group that seized the city last year while al Qaida-linked Sunni militants battle across the country.
But the Houthi were the targets of Friday’s attacks, which were quickly claimed by Sunni militants from al-Qaida.
The United States has been waging drone warfare against al-Qaida militants in Yemen.
“Let the polytheist Houthis know that the soldiers of the Islamic State will not rest and will not stay still until they extirpate them,” the group said in a statement claiming responsibility for the attacks posted on Twitter, Reuters said.
“God willing, this operation is only a part of the coming flood,” the statement said.
Victims included Almortada al-Mahatwary, a leader in Yemen’s Shi’ite Zaidi sect, according to Houthi-controlled al-Masirah television.
Television footage showed young men in traditional Yemeni clothes carrying lifeless bodies, some dripping with blood, out of the mosque.
“I was going to pray at the (Badr) mosque then I heard the first explosion, and a second later I heard another one,” a witness told Reuters.
The White House said Friday that it condemned the bombings but was unable to confirm whether the attackers were affiliated with Islamic State.
A spokesman for U.S. President Barack Obama said there was no clear operational link between the people who carried out Friday’s attacks in Yemen and Islamic State fighters in Iraq and Syria.
U.N. Secretary-General Ban Ki-moon condemned “the terrorist attacks” and called on all sides “to immediately cease all hostile actions and exercise maximum restraint,” Reuters said.
