A videograb shows wounded people in hospital following a stampede at a charity distribution event in Sanaa on Thursday. AFP

At least 85 people were killed and hundreds injured in a crush at a Ramadan cash handout in Yemen early on Thursday, as the country suffered one of its worst tragedies just as optimism was growing over its bitter civil war.

Three people were detained over the stampede in Sanaa, Yemen's rebel-held capital, after large crowds gathered at a school to receive gifts of 5,000 rial (about $8) for the end of Ramadan.

Harrowing footage screened by the Houthi rebels' Al Masirah TV showed a tightly packed crowd screaming and shoving, unable to move, while others attempted to haul stricken people out of the crush.

Other shots showed dead bodies on the ground as the panic continued. Afterwards, piles of abandoned sandals, clothing and a crutch littered the scene, while an investigator in white protective gear collected evidence.

"It was a huge crowd. They fell on me, and I got hurt," an injured child told Al Masirah from his hospital bed.

A Houthi security official speaking on condition of anonymity told reporters that at least 85 people were killed and "more than 322" injured, 50 of them seriously.

"Women and children were among the dead," the official said. A health official confirmed the toll.

The tragedy comes just ahead of Eid Al Fitr and punctures a buoyant mood over the war in the country, following peace talks and an exchange of nearly 1,000 prisoners last week.

Eyewitnesses said gunfire sparked a stampede after crowds gathered at the school, in Sanaa's historic Bab Al Yemen district, to receive the handouts from a businessman.

The head of the Houthis' Supreme Revolutionary Committee, Mohamed Ali Al-Houthi, blamed "overcrowding," saying people were packed in a narrow street leading to the school's back entrance.

Once the gates opened, the crowd streamed into a tight staircase leading to the courtyard where the distribution was taking place.

"Citizens were informed a week ago that sums of money would be disbursed without ID verification," said one witness.

"People flocked in a huge way, the gate opened, and with the large numbers, the stampede happened."

The Houthis' political chief Mahdi Al Mashat said a committee had been formed to investigate, and a Houthi security official said three people had been detained on suspicion of involvement.

After the stampede, families converged on hospitals but many were not allowed to enter as senior officials were also visiting the dead and wounded.

At the school, heavily deployed security forces were seen blocking relatives from entering the facility to locate family members.

Footage from one hospital showed dazed and bandaged survivors recovering in a ward, some with visible wounds on their limbs and heads.

Agence France-Presse