|Armed tribesmen say they are now backing government troops trying to retake Zinjibar, capital of Abyan [EPA]
Yemeni forces backed by armed tribesmen have launched an offensive against al-Qaeda-affiliated fighters to retake Zinjibar, capital of the southern Abyan province, officials say.
The tribesmen, though previously allied to the fighters who call themselves Partisans of Sharia, now say they oppose the group.
Up to 20 al-Qaeda-linked fighters were killed and dozens on both sides were injured on Sunday, according to a local government official.
He said 35 fighters have been killed since the offensive began on Saturday night, but only confirmed the death of two soldiers.
Medical workers in Zinjibar declined to give an estimate of soldiers' deaths, saying they were too overwhelmed with casualties entering the hospital.
Zinjibar lies east of the strategic Bab al-Mandab strait, through which about three million barrels of oil pass daily.
After months of fighting, dozens have been killed and an estimated 54,000 civilians have fled Abyan.
The province descended into daily bloodshed as the army faced a rising challenge from the entrenched al-Qaeda-linked fighters.
Mass protests in Yemen demanding that the president, Ali Abdullah Saleh, leave office have entered their sixth month, paralysing several cities and pushing the country into political limbo.
Amid the unrest in Abyan, anti- and pro-government protesters rallied on Sunday across Yemen to mark 33 years of rule by Saleh, who is convalescing in the Saudi capital, Riyadh, after being injured by a bomb blast on his presidential compound.
The previous day, protest leaders announced in Sanaa, the Yemeni capital, the formation of a shadow government in a move to take the lead in the fight to keep Saleh out.
Opposition groups accuse Saleh of letting his forces ease up in the south to convince Yemen's allies that only he stood in the way of an al-Qaeda takeover.
The US and Saudi Arabia are keen to halt the chaos in Yemen, fearing the growing power vacuum gives extra room to al-Qaeda's regional wing.
Both countries have been targets of failed attacks by al-Qaeda, organised in Yemen.
Following weeks of pleas for support from a besieged military brigade near Zinjibar, the government sent the first reinforcements on Saturday, aiming to drive the fighters out of the seaside city.
"The head of the defence ministry sent reinforcements including tanks, rocket launchers and 500 extra soldiers," a local official said.
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"These forces began attacking [the city] backed by heavy tank shelling and rocket attacks from naval ships in order to liberate the 25th Brigade just outside Zinjibar and under siege for over a month."
Tribesmen who joined the weekend offensive say they have sent about 450 men to Zinjibar.
They had begun to plan attacks on the fighters last week, saying the army had been ineffective.
The fighters seized the city of Jaar in March and Zinjibar in May, and later took control of a football stadium outside Zinjibar which was being used as a makeshift army base.
Army units have been engaging the fighters around the football field since dawn, residents and a local official said, and armoured vehicles shelling the area have destroyed part of the stadium.
Tribes against al-Qaeda
In the past week, tribes have regained control of a number of towns in Abyan previously held by al-Qaeda, according to a leader of the local Nakhiine tribe.
Mohammed Ahmed al-Nakhai, who is also the most senior local official in the town of Mudiyah, said: "The tribes have formed an alliance in the province to expel al-Qaeda from the cities and villages, as the presence of these militants is a danger to inhabitants."
Tribesmen in Mudiyah were the first to move to expel al-Qaeda, and the fighters withdrew from the town after mediators and tribesmen set up barricades around the entrances, al-Nakhai said.
Tribesmen in other towns such as Mehfed and Jaar, which lies just north of Zinjibar, have also pushed al-Qaeda fighters out of their areas, he said.
In Mudiyah and elsewhere in Abyan, al-Qaeda had controlled government offices, had armed men patrolling the streets, and banned publications they did not approve of, residents said.
Many members of tribes in Abyan had supported or joined al-Qaeda in the past, for the reason that they opposed the Sanaa government and viewed al-Qaeda as a fellow resistance group.
But now, most of the tribes in Abyan have turned against al-Qaeda, except for those in the town of Loder who have been meeting to decide what position to take, according to the residents.