Gunmen on Saturday seized Yemeni President Abdrabuh Mansur Hadi’s chief of staff, whose nomination as prime minister last year was rejected by Iranian-backed Houthi Shi’ite terrorists controlling the capital, an official said.

“An armed group set up a checkpoint in Hada,” a southern district of the capital city Sana’a, and “captured (Ahmed Awad bin) Mubarak with his companions,” an official from the national dialogue secretariat told AFP.

Mubarak is secretary general of the national dialogue on a political transition following the 2012 resignation of veteran president Ali Abdullah Saleh, which came after a bloody year-long uprising.

The senior politician was “driven away to an unknown location,” the official said, adding that the abductors “are suspected of being Houthi militiamen.”

Yemen has been dogged by instability since Saleh’s ouster, with the Houthis and Al-Qaeda seeking to fill the power vacuum.

Mubarak, a southerner, was one of the representatives in the dialogue of the Southern Movement, which seeks autonomy or secession for the formerly independent south, which until 1990 was a Communist state. The two sides went through a bloody civil war in 1994.

Hadi appointed Mubarak as prime minister last October, but Mubarak turned down the job following strong opposition by Houthi fighters who overran Sana’a last September 21, and by Saleh’s General People’s Congress Party.

The Houthis are widely believed to be backed by Saleh.

The UN Security Council last November slapped sanctions – including a visa ban and asset freeze – on Saleh and two rebel commanders for threatening peace.

AFP contributed to this report.