Yemen's Iran-aligned Houthi movement has said it launched missile and drone attacks on on a military parade in the seat of the Saudi-backed government.

More than 30 people were killed in the attack in Aden on Thursday, according to medical and security sources.

A witness told Reuters they saw nine bodies on the ground after an explosion hit a military camp belonging to the Yemeni Security Belt forces backed by the United Arab Emirates (UAE). The force is a member of the Saudi-led military coalition battling the Houthis.

The attack killed at least 32 people, a medical and a security source said.

Medecins Sans Frontieres tweeted that tens of wounded were hospitalised.

Soldiers screamed and ran to lift the wounded and place them on trucks. Red berets lay on the ground in pools of blood.

The children wounded in Yemen's war Show all 15 1 /15 The children wounded in Yemen's war The children wounded in Yemen's war Save the Children Child Protection staff pictured alongside Ahmed and his family to ensure ongoing physical and mental support for Ahmed at home through regular follow up visits. August 15, 2018 Ali Ashwal / Save the Children The children wounded in Yemen's war Ahmed, a 15 year-old, is lying on his bed after his leg and arm were injured during an airstrike in a market in Hudaydah. His leg is protected with Gypsum after several successful surgeries. Ali Ashwal / Save the Children The children wounded in Yemen's war Save the Children Child Protection staff pictured alongside Ahmed and his family to ensure ongoing physical and mental support for Ahmed at home through regular follow up visits. August 15, 2018 Ali Ashwal / Save the Children The children wounded in Yemen's war Save the Children Child Protection staff pictured alongside Ahmed and his family to ensure ongoing physical and mental support for Ahmed at home through regular follow up visits. August 15, 2018 Ali Ashwal / Save the Children The children wounded in Yemen's war Save the Children Child Protection staff pictured alongside Ahmed and his family to ensure ongoing physical and mental support for Ahmed at home through regular follow up visits. August 15, 2018 Ali Ashwal / Save the Children The children wounded in Yemen's war Ahmed, a 15 year-old, is lying on his bed after his leg and arm were injured during an airstrike in a market in Hudaydah. His leg is protected with Gypsum after several successful surgeries. August 15, 2018 Ali Ashwal / Save the Children The children wounded in Yemen's war Save the Children Child Protection staff pictured alongside Ahmed and his family to ensure ongoing physical and mental support for Ahmed at home through regular follow up visits. August 15, 2018 Ali Ashwal / Save the Children The children wounded in Yemen's war Ahmed, a 15 year-old, is lying on his bed after his leg and arm were injured during an airstrike in a market in Hudaydah. His leg is protected with Gypsum after several successful surgeries. August 15, 2018 Ali Ashwal / Save the Children The children wounded in Yemen's war Ahmed, a 15 year-old, is lying on his bed after his leg and arm were injured during an airstrike in a market in Hudaydah. His leg is protected with Gypsum after several successful surgeries. Ali Ashwal / Save the Children The children wounded in Yemen's war Iman* is six years old and lives in Altuhaitah district, Western Hodeidah, with her parents and six siblings. Her father is a daily labourer and earns around 500 – 1000 Yemeni Riyals (1 – 2 USD) each day. On 26th June, Iman was playing in her backyard when an airstrike hit her neighbour’s house. Shrapnel from the attack reached Iman’s home and she severely injured her neck, hand, and leg. Iman’s three-month-old brother also sustained minor injuries from the shrapnel. June 07 2018 Ali Ashwal / Save the Children The children wounded in Yemen's war Iman* is six years old and lives in Altuhaitah district, Western Hodeidah, with her parents and six siblings. Her father is a daily labourer and earns around 500 – 1000 Yemeni Riyals (1 – 2 USD) each day. On 26th June, Iman was playing in her backyard when an airstrike hit her neighbour’s house. Shrapnel from the attack reached Iman’s home and she severely injured her neck, hand, and leg. Iman’s three-month-old brother also sustained minor injuries from the shrapnel. June 07 2018 Ali Ashwal / Save the Children The children wounded in Yemen's war Iman* is six years old and lives in Altuhaitah district, Western Hodeidah, with her parents and six siblings. Her father is a daily labourer and earns around 500 – 1000 Yemeni Riyals (1 – 2 USD) each day. On 26th June, Iman was playing in her backyard when an airstrike hit her neighbour’s house. Shrapnel from the attack reached Iman’s home and she severely injured her neck, hand, and leg. Iman’s three-month-old brother also sustained minor injuries from the shrapnel. June 07 2018 Ali Ashwal / Save the Children The children wounded in Yemen's war Iman* is six years old and lives in Altuhaitah district, Western Hodeidah, with her parents and six siblings. Her father is a daily labourer and earns around 500 – 1000 Yemeni Riyals (1 – 2 USD) each day. On 26th June, Iman was playing in her backyard when an airstrike hit her neighbour’s house. Shrapnel from the attack reached Iman’s home and she severely injured her neck, hand, and leg. Iman’s three-month-old brother also sustained minor injuries from the shrapnel. June 07 2018 Ali Ashwal / Save the Children The children wounded in Yemen's war A boy injured by in the attack on a school bus in Saada, August 9th. Dozens of children aged between 6 and 14 have been killed with many more injured, after the school bus they were travelling in was hit by an airstrike in the town of Dhahyan in Saada governorate in northern Yemen. August 09, 2018 Save the Children The children wounded in Yemen's war A boy injured by in the attack on a school bus in Saada, August 9th. Dozens of children aged between 6 and 14 have been killed with many more injured, after the school bus they were travelling in was hit by an airstrike in the town of Dhahyan in Saada governorate in northern Yemen. August 09, 2018 Save the Children

The Houthi's official channel Al Masirah TV said the group had launched a medium-range ballistic missile and an armed drone at the parade, which it described as being staged in preparation for a military move against provinces held by the movement.

A pro-government military source and security sources said Brigadier General Muneer al-Yafee, a leading figure of the southern separatists, was among those killed.

“The blast occurred behind the stand where the ceremony was taking place at Al Jalaa military camp in Buraiqa district in Aden,” the witness said. “A group of soldiers were crying over a body believed to be of the commander.”

Mr Yafee had just stepped off the stage to greet a guest when the explosion took place. Flags of the former South Yemen and those of leading coalition members were fluttering as the military band was waiting for its cue to start playing.

The Western-backed Sunni Muslim coalition led by Saudi Arabia and the UAE intervened in Yemen in 2015 to try to restore the internationally recognised government ousted from power in the capital Sanaa by the Houthis in late 2014.

The government of Abdu-Rabbu Mansour Hadi controls the southern port city of Aden. The Houthi movement, which says its revolution is against corruption, holds Sanaa and most of the biggest urban centres in the Arabian Peninsula nation.

The parade “was being used to prepare for an advance on Taiz and Dalea,” Masirah reported a Houthi military spokesman as saying.

There was no immediate comment from the Yemeni government or the coalition.

Last month the UAE said it was scaling down its presence in Yemen, pulling some troops from areas including Aden and the western coast deployed for operations against the Houthis in the main port city of Hodeidah, where a UN-brokered ceasefire has been in place since last December.

An Emirati official said the UAE would not leave a vacuum in Yemen as it had trained 90,000 Yemeni forces, drawn from among southern separatists, including Security Belt forces, and coastal plains fighters.

The Houthis have stepped up cross-border missile and drone attacks on Saudi cities and the coalition has responded with air strikes on Houthi military sites, mostly around Sanaa.

The escalating violence could complicate UN-led efforts to implement a troop withdrawal in Hodeidah, the main entry point for Yemen's commercial and aid imports, to pave the way for political talks to end the war amid mistrust among all parties and competing agendas of Yemen's fractious groups.

The more than four-year conflict, widely seen in the region as a proxy war between Saudi Arabia and Iran, has killed tens of thousands and pushed Yemenis to the brink of famine.

In a separate attack in another district of Aden on Thursday, an explosives-laden car blew up at a police station killing three soldiers, a security source said.

It was not clear if the incidents were related. Previous car attacks in Yemen have been carried out by Islamist militant groups like al Qaeda.