At least 78 people have been killed in a crush at a school in Yemen's rebel-held capital, Sanaa, during a charity event for Ramadan, officials say.

The incident began after hundreds crowded into a narrow street in the Bab al-Yemen area late on Wednesday to get handouts of $9 (£7) from a merchant.

Video showed people screaming for help and others trying to pull them free.

Later footage appeared to show dozens of bodies on the ground, as well as shoes and clothing strewn over steps.

Officials from the rebel Houthi movement accused organisers of failing to co-ordinate with local authorities and said they had been detained.

Yemen has been devastated by a civil war that escalated in 2015, when the Iran-aligned Houthis seized control of large parts of the west of the country from the internationally-recognised government and a Saudi-led coalition intervened in an effort to restore its rule.

The fighting has reportedly left more than 150,000 people dead and triggered one of the world's worst humanitarian crises, with two thirds of the population - 21.7 million people - in need of some form of aid.

Poor people made their way to the Maeen School in central Sanaa on Wednesday night after being told that a local merchant would be handing out zakat (alms) to mark the end of the Islamic holy month of Ramadan.

The head of the Houthis' Supreme Revolutionary Council, Mohammed Ali al-Houthi, posted a photo on Twitter apparently showing hundreds of people queuing outside the school before the crush.

Mr Houthi said the merchant received people via a back gate that was reached by a narrow street and steps. This resulted in overcrowding and a crush when the gate was opened, he added.

He also blamed the Saudi-led coalition for causing an "economic catastrophe" with its military campaign against the rebels and blockade of the country.

The Associated Press quoted two witnesses who said Houthi forces fired into the air in an attempt at crowd control, apparently hitting an electrical wire which resulted in an explosion. This caused panic that led to the crush, they added.

However, witnesses told the BBC that the Houthis fired shots into the air after the crush began in order to clear a path to the casualties.

One of the witnesses said the crowd was forced to gather in the narrow street because the school's main gate was closed. The crush happened as people in the queue were pushed up the steps into others who had received their handouts and were trying to leave, he added.

A health ministry official said women and children were among the 78 people killed in the crush.

Another 77 people were injured, according to the ministry. Thirteen were in a critical condition in hospital on Thursday, while the rest were discharged after receiving treatment, it added.

"It was a huge crowd. They fell on me, and I got hurt," a boy who was injured in the crush told rebel-run Al-Masirah TV at one hospital.

The president of the Houthis' Supreme Political Council, Mahdi al-Mashat, expressed his condolences to the victims' families and ordered the formation of a committee to investigate the incident, according to Al-Masirah.

The head of the Houthis' General Zakat Authority meanwhile said it would pay $2,000 (£1,600) to each family who lost a relative, while the injured would get around $400 (£322).