Saudi Arabia released seven Yemenis in exchange for one of its soldiers, the kingdom's news agency reported Wednesday. It marked the first announced prisoner swap since a Saudi-led coalition of Arab countries went to war against Yemen's Shiite rebels nearly a year ago.

The Saudi military and the rebels known as Houthis frequently clash along the kingdom's southern border with Yemen. The statement, carried by the Saudi Press Agency, did not specify if the Houthis had been holding the soldier who was released.

SPA said Yemeni tribal leaders coordinated the prisoner swap that led to the release of Cpl. Jaber al-Kaabi. It also said Yemeni tribal figures helped facilitate the delivery of aid across the border into Yemeni villages.

The statement said the seven Yemenis had been detained in areas of military operations near the border, but did not give details on when the Yemenis and the soldier had been detained nor where the exchange took place.

In September, the Houthis released a video purporting to show another Saudi corporal, named Ibrahim al-Hakimi, being held captive.

The Yemeni capital of Sanaa and the northern region of the country where Houthis are in control have reported relative calm in recent days.

It comes as a delegation of tribal leaders from Yemen's border area were in the Saudi capital of Riyadh this week to discuss prisoner swaps, according to Mohammed Ali al-Emad, a brother of a top Houthi politician with knowledge about the talks. He told The Associated Press the talks are aimed at paving the way for possible cease-fire negotiations because the warring sides "have realized that war so far has failed to force any of the two to retreat."

Speaking to the Arabic satellite channel Al-Arabiya, Saudi-led coalition spokesman Brig. Gen. Ahmed al-Asiri said Wednesday there were no direct talks with the Houthis, but that there were talks with tribal figures who are serving as mediators.

The Houthis took over Sanaa in September 2014, and the Saudi-led coalition began airstrikes against the rebels in March 2015. Al Qaeda militants, the Islamic State group, southern separatists, and other militants have capitalized on the chaos of Yemen's civil war.

Clashes also erupted Wednesday in the southern Yemeni port city of Aden, between the guards at a presidential palace and gunmen who were recently let go from the presidential guard.

The gunmen attacked the guards and insisted they return to their jobs even if by force, security officials said.

As the attack unfolded, several families left the area after a mortar fell on one of the houses. Ambulances ferried three wounded civilians to hospital, according to medical officials, while loud explosions were heard in the area.

A doctor was also shot and killed as she tried to administer first aid to the wounded amid the clashes, according to medical officials.

Both the medical and security officials spoke on condition of anonymity as they were not authorized to talk to reporters.

The nearly yearlong war has killed more than 6,000 people and created what the United Nations warns is a "humanitarian catastrophe," with some 7.6 million people "severely food insecure" and 3.4 million children out of school.

The conflict pits the Yemeni government, backed by the Saudi-led coalition, against the Houthis and loyalists of Yemen's former longtime president. The Houthis are also allies of Saudi Arabia's regional rival Iran.