Forces loyal to Yemen's president are scrambling to enlist thousands of troops to resist an expected attack on his southern stronghold by militiamen who have seized swathes of the country.
The recruitment drive comes as fears grow that the impoverished Arabian Peninsula country, a front line in the US battle against Al-Qaeda, is sliding towards all-out civil war.
In the southern city of Aden, chaos erupted as would-be recruits jostled to sign up to defend the embattled leader against the advancing Huthi Shiite militia.
"We came to Aden to do our duty, at the request of President Abedrabbo Mansour Hadi," said Saqr al-Moghrabi.
Like some others seeking to enlist, he formerly served under the command of rogue general Abdel Hafedh al-Sakkaf, who sided with the Huthis before fleeing Aden.
"We feel lost," said Moghrabi.
"The new commander played tricks on us," added Iman al-Sharaabi, saying he hoped to secure employment and a salary fighting for Hadi, a southerner.
The Western-backed president escaped the militia-held capital Sanaa in February and took refuge in Aden.
He has since launched a campaign to sign up 20,000 soldiers to reinforce his troops, targeting young Yemenis from the south.
Several thousand have already registered but they must still be trained and armed, said one Hadi aide who spoke on condition of anonymity.
The slow pace of the process has not dampened the enthusiasm of the recruits, who once registered take to the streets with vows to "kill the Huthis".
They face an enemy that has made sweeping gains since pushing south from its northern bastion and overrunning the capital in September.
Hadi's forces made no attempt to prevent the Huthis from entering the central city of Taez on Sunday and taking over its airport and other facilities.
Taez, just 180 kilometres (110 miles) north of Aden on the road to Sanaa, is seen as a strategic entry point to Hadi's refuge.
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- Fears of 'protracted conflict' -
UN Secretary General Ban Ki-moon's special adviser on Yemen has voiced fears that the rival forces will remain deadlocked, and warned that the country is sliding towards "civil war".
"It would be an illusion to think that the Huthis could mount an offensive and succeed in taking control of the entire country," Jamal Benomar told an emergency meeting of the UN Security Council on Sunday.
"It would be equally false to think that President Hadi could assemble sufficient forces to liberate the country from the Huthis," he added.
"Any side that would want to push the country in either direction would be inviting a protracted conflict in the vein of an Iraq-Libya-Syria-combined scenario."
Hadi, backed by the Sunni rulers of neighbouring Saudi Arabia, has pledged to fight the influence of Shiite Iran, which is accused of backing the Huthis.
He has sought the support of powerful Sunni tribes from the south and other regions.
Their backing is seen as key to controlling deeply tribal Yemen, but Hadi has struggled to command the same level of loyalty that former president Ali Abdullah Saleh enjoyed.
The longtime strongman was forced from power in 2012 after a year-long popular uprising.
He has been accused of working with the Huthis to restore his influence, and the Shiite militiamen have the support of Saleh loyalists in the army.
On Hadi's side are the Popular Resistance Committees, a locally recruited militia which appears highly motivated and well-prepared for battle.
Hadi also enjoys the loyalty of his defence minister General Mahmud al-Subaihi, reputedly a skilled military leader, as well as tribal fighters.
On a road in the north of Aden, tribesmen have taken up positions to resist any Huthi attack.
"We have tried to avoid war, just as the president of the country tried several times to avoid division. But the Huthis have not heard this message," said tribal chief Abdel Latif Essayed.