Thousands of marchers took to the streets of Yemen's capital, Sana'a, Sunday to protest an apparent Saudi-led coalition airstrike that killed more than 140 people at a funeral on Saturday. A United Nations observer said more than 500 others were wounded.
Protesters gathered outside of U.N. offices in the capital chanting "death to al-Saud," the Saudi royal family.
The protests came a day after bombs hit a funeral hall where mourners marked the death of the father of a prominent Houthi rebel official. Reports and video from the scene showed widespread destruction and rescuers collecting body parts scattered through the ruins of the wrecked facility.
Saudi coalition officials initially denied any role in the bombing, but later announced an investigation of what they described as a "regrettable and painful" attack.
Yemeni officials said the dead and wounded included military and security personnel from the Shi'ite Houthi rebel regime seeking to oust the internationally recognized, Saudi-backed government of President Abdu Rabu Mansour Hadi.
In a televised address Sunday, Houthi leader Abdul-Malek al-Houthi described the dead as martyrs, and said the bombings had been carried out with U.S.-made weaponry. He also urged his followers to launch further attacks on Saudis at the Yemen-Saudi border.
Late Saturday, the Obama administration announced an urgent review of U.S. support for the Saudi-led coalition.
U.S. National Security Council spokesman Ned Price said "we are deeply disturbed by reports of today's airstrike," which appear to "continue the troubling series of attacks striking Yemeni civilians.
"U.S. security cooperation with Saudi Arabia is not a blank check," Price said, adding that U.S. support for the Saudi-led operation in Yemen has already been "significantly reduced."
A spokesman for U.N. Secretary-General Ban Ki-moon said "any deliberate attack against civilians is utterly unacceptable and calls for a prompt and impartial investigation."
By late Sunday, authorities had produced no definitive evidence on details of the blasts, and at least one early report suggested the involvement of suicide bombers.
But most accounts said the devastation was caused by missiles fired by one or more warplanes - possibly the most damaging attack since the Saudi air campaign in Yemen began last year.
The Saudi-led coalition of regional Sunni governments that has been attacking Houthis in Yemen in support of President Hadi Since March of 2015. A U.N. report says the coalition airstrikes have killed nearly 4,000 people.
Houthi rebels, alleging years of discrimination by the Sana'a government, launched a rebellion in 2014 aimed at wresting power from President Hadi. Since then, more than 10,000 people, most of them civilians, have been killed.