Yemen’s main southern city of Aden has been shaken by double attacks as a missile fired by rebels hit a military parade and suicide bombers blasted a police station.

At least 51 people were killed in the deadliest day in nearly two years in the de facto capital of the US and Saudi-backed side in Yemen’s civil war.

Most of the dead came from the missile strike, which struck a parade of newly graduated fighters belonging to a militia loyal to the United Arab Emirates (UAE), known as the Security Belt.

Civilians and security forces gather at the site of the deadly attack in Aden
Civilians and security forces gather at the site of the deadly attack in Aden (AP/Nariman El-Mofty)

Among the dead was a senior commander in the militia, Monier al Yafie, also known by his nickname Aboul Yamama, a security official told The Associated Press.

Aboul Yamama had just given a speech to the graduates and had stepped offstage to get a drink of water when the missile struck the al-Galaa base. His body was torn in half, the official said.

At least 40 people were killed at the base on Aden’s western outskirts.

The earlier attack at the police station in the central Omar al-Mokhtar neighborhood of Aden, was believed to have been carried out by Islamic militants.

The violence left at least 56 people wounded.

It pointed to the multiple dangers facing the port city, even though Yemen’s four-year-old civil war is locked in a stalemate.

The northern part of Yemen is controlled by the Iranian-backed rebels, known as Houthis, who have positions on front lines as close as 60 miles from Aden and often hit it and nearby areas with missiles or bombs dropped by drones.

Houthi rebel fighters in Sanaa, Yemen
Houthis control the northern part of Yemen (AP/Hani Mohammed)

Islamic militants — from both al-Qaida and an Islamic State group affiliate — also operate in Aden. Their mass bombings had become less frequent, though assassinations and shootings regularly take place.

Aden is also at the centre of stormy and often violent divisions within the Saudi-led coalition fighting the Houthis. Ostensibly, the coalition aims to restore Yemen’s internationally recognised government, driven out of the capital of Sanaa in the Houthis’ 2014 takeover.

But the UAE, a coalition member, dominates Aden and the south through militias like the Security Belt that it funds and arms, sidelining the government.

Pro-UAE and pro-government militias waged bloody battles in Aden in early 2017 — fighting that Aboul Yamama was involved in. Since then, such violence has eased.

But the UAE has begun withdrawing thousands of its troops from Yemen, saying it wants to give a boost to peace talks with the Houthis. Its reduced presence could open up factional tensions once more.

The Houthis claimed responsibility for the missile strike in a statement on their website by a military spokesman, Brigadier General Yehia Sarea. He said Houthis had fired a medium-range ballistic missile at the parade.

No group immediately claimed responsibility for the police station attack.