Shiite rebels who have been expanding their control in Yemen have clashed with Al-Qaeda militants in the centre of the volatile country, leaving 12 dead, a security official said Wednesday.

Five rebels, six suspected Al-Qaeda militants and a civilian were killed late on Tuesday during the fighting in Rada in central Yemen, the security official and tribal sources said.

Militants from Al-Qaeda, which is active in several provinces of Yemen, confronted the rebels who tried to expand out of Rada, which is in Baida province southeast of the capital Sanaa.

The rebels, known as Huthis, have a presence in some villages of the Rada district and continue to control the capital after they overran it unopposed on September 21.

Officially known as Ansarullah, the rebels stretched their control to the shores of the Red Sea on Tuesday, seizing control of the Hudeida port city hours after a new premier was named in a bid to defuse the country's political crisis.

The rebels, traditionally based in the north, have been battling troops and Sunni militants in recent months as part of their bid to spread their control across the country.

Al-Qaeda in the Arabian Peninsula, the group's Yemeni branch, is considered by the United States to be the most dangerous affiliate and its leaders have been targeted repeatedly by US drone strikes.

The group has vowed to fight the Shiite rebels in defence of Yemen's Sunni majority, and has also repeatedly targeted security forces, particularly in the south and east.

The impoverished country has been wracked by political turmoil and sporadic violence since an uprising toppled strongman Ali Abdullah Saleh in 2012.