Sanaa: Shiite rebels sweeping across Yemen clashed with Sunni tribesmen and Al-Qaeda militants on Friday in violence that left 20 people dead, officials said.
Twelve Shiite rebels and eight tribesmen died in a battle for control of the predominantly-Sunni provincial capital Ibb which the rebels overran earlier this week, local government officials told AFP.
Explosions were heard across the city as the rebels, known as Huthis, came under rocket-propelled grenade fire from tribesmen in the surrounding countryside, witnesses said.
The fighting came after hundreds of armed tribesmen demonstrated outside the governor`s office in the city on Thursday evening demanding the withdrawal of the rebels.
Deputy governor Ali al-Zanam said the rebels had told him they advanced into Ibb to "confront what they described as security gaps and hunt down wanted" Al-Qaeda militants, local media reported.
The rebels clashed with Al-Qaeda militants overnight in Baida province further east, leaving "dozens" of casualties, tribal and security sources said.
The rebels have clashed repeatedly with Al-Qaeda in the province since Tuesday.
The Sunni extremists have vowed to resist the Shiite rebel advance in the impoverished country, which is located next to oil-rich Saudi Arabia and key shipping routes in the Gulf of Aden.
Rival groups are seeking to exploit a power vacuum in impoverished Yemen, which has been in political deadlock since the rebels took control of the capital Sanaa on September 21.
The rebels, who were previously based in the northern highlands where Yemen`s Zaidi Shiite minority is concentrated, have since made significant advances in provinces south of Sanaa.
They took the Sunni majority Red Sea port city of Hudeida on Monday, and on Wednesday appeared to have taken control, unopposed, of Dhamar and Ibb provinces, security officials said.
The steady expansion of the rebels has increased the threat of an open confrontation with Al-Qaeda.
Al-Qaeda claimed responsibility for a powerful suicide bombing that killed 47 people at a gathering of Huthi supporters in Sanaa earlier this month.
An unknown assailant on a motorbike hurled a grenade at a Huthi post in the capital on Wednesday, killing two people and wounding two others, rebels said.
And suspected Al-Qaeda militants executed a local Huthi chief, Khalil al-Riyami, who was apparently captured during Tuesday`s clashes in Baida province.The Huthi rebels set up armed protest camps in Sanaa in August, calling for the government to step down and demanding more power in state institutions.
Late on Thursday, the rebels began dismantling their protest camps in Sanaa.
Protest organisers said in a statement the move was aimed at implemented the terms of a UN-brokered ceasefire agreement, calling on Huthis to withdraw from Sanaa and disarm after the appointment of a new prime minister.
On Monday, beleaguered President Abdrabuh Mansur Hadi named Yemen`s envoy to the United Nations Khalid Bahah as his new premier, a nomination the rebels appeared to approve.
But leading Huthi protest organiser Khalid al-Madani told supporters in Sanaa that dismantling the protest camps "does not mean that the revolt is over."
"We have now moved on to government and state institutions to uproot corruption," he said.
Observers said, however, that the Huthis were dismantling their protest camps amid fear they could come under fresh Al-Qaeda attacks.
Al-Qaeda`s Yemen-based franchise is classified by the United States as the network`s deadliest franchise.
On Friday it urged Muslims worldwide to support Islamic State group jihadists in Syria and Iraq in the face of attacks by a US-led military coalition.
Meanwhile Sanaa residents said the Huthi rebels have widened their deployment across the capital since Thursday, erecting new checkpoints and seizing vehicles that have no number plates, in fear of attacks.
The rebels` Zaidi sect, an offshoot of Shiite Islam, makes up approximately a third of the Sunni-majority country`s population.