Yemeni local tribal mediation on Sunday succeeded in releasing a leader of the pro-secession Southern Movement after more than 11 years of detention, in return for the release of 33 prisoners of the Houthi group.

Yasser AlHadi, head of the prisoners' file in the pro-secession Southern Movement, told Xinhua that "Brigadier Ahmed Omar Marqashi was released by a mediation after spending about a decade in the central prison of Sanaa on malicious charges."

"The mediation composed of senior tribal figures succeeded in freeing Marqashi in exchange for the release of 33 Houthi prisoners from the southern forces custody in Aden," said AlHadi.

High-ranking tribal leaders from the country's southern provinces and senior military officials attended the prisoner swap, he said, but didn't mention details about place of the operation.

Brigadier Marqashi, 56, is considered as one of the leaders who established the Southern Movement, demanding the secession of southern Yemen from its north.

Marqashi was arrested in the southern port city of Aden in February 2008 and transferred to central prison of the country's capital Sanaa during the rule of former Yemen's President Ali Abdullah Saleh.

It's not the first prisoners' swap to take place between the warring factions in Yemen according to efforts exerted by local tribal and social figures, but similar ones occurred during the last years.

Yemen has been mired into a civil war since late 2014, when Shiite Houthi rebels overran much of the country and seized all northern provinces, including the capital Sanaa.

The civil war has killed more than 10,000 people, mostly civilians, displaced 3 million others, and pushed Yemen to the brink of famine.