Hadi loyalists advance in Yemen's Aden
Yemeni fighters against Houthi rebels ride military vehicles on a street in the port city of Aden.
Aden - Popular Resistance fighters recaptured the provincial government headquarters in the Mualla district opposite Aden's main commercial port.
Loyalists of Yemen's exiled president, buoyed by their recapture of the airport, seized more ground in second city Aden on Wednesday as they pressed their biggest fightback yet against Houthi rebels.
The offensive, dubbed Operation Golden Arrow, is the first major advance by the loyalists since the rebels entered the port city in March, forcing President Abedrabbo Mansour Hadi into exile in neighbouring Saudi Arabia.
Despite an appeal from US President Barack Obama to The Custodian of Two Holy Mosques, King Salman bin Abdulaziz Al Saud, for an urgent end to the fighting, Saudi-led warplanes carried out six raids on rebel positions before dawn, witnesses and military sources said.
Popular Resistance fighters - a southern militia that has been the mainstay of support for Hadi - recaptured the provincial government headquarters in the Mualla district opposite Aden's main commercial port, militia spokesman Ali Al Ahmadi said.
They also advanced in Aden's Crater downtown district, where a presidential palace is located, amid heavy fighting, he added.
And pro-government fighters entered the small commercial port in Mualla itself, near the main port which the rebels had failed to take, according to military sources.
General Fadhl Al Hasan, leading pro-government forces' operations in Aden's west, said that his troops have also captured the coastal road overlooking the strategic Bab Al Mandeb Strait between Yemen and Djibouti.
The road links Aden to the rebel-held city of Mocha, home to a port near Bab Al Mandeb.
"The Resistance is at the gates of the city of Mocha," through which rebel military reinforcements used to arrive from northern cities under their control, said Hasan.
On Tuesday, the Popular Resistance, backed by reinforcements freshly trained and equipped in Saudi Arabia, retook the airport and much of the surrounding Khormaksar diplomatic district.
"After the recapture of Khormaksar, there was a collapse in the ranks of the Houthis and their allies," renegade troops loyal to Hadi's predecessor Ali Abdullah Saleh, Ahmadi said.
It was the defection of the 39th Armoured Brigade on March 25 that had enabled the rebels to take the airport.
A Western diplomat in Riyadh said that, if the airport and environs can be secured, it could be used to deliver supplies to loyalist forces.
"This could be the first step to a beachhead," he said.
Much of Aden has been reduced to rubble by four months of ferocious fighting.
The retreating rebels pounded residential districts in the north and east of Aden with Katyusha multiple rocket launchers, provincial officials said.
At least 12 civilians were killed and 105 wounded, Aden health department chief Al Khader Laswar said.
Eight loyalist militiamen were killed and 30 wounded in the fighting, Laswar added.
There was no immediate word on rebel losses.
Renegade troops loyal to former president Ali Abdullah Saleh have been fighting alongside the Houthis, who still control the capital Sanaa as well as most of the north.
The offensive comes after the failure of a UN-declared truce that was to have taken effect just before midnight on Friday to allow the delivery of desperately needed relief supplies.
The White House said Obama spoke by telephone with the Saudi King on Tuesday "about the urgency of stopping the fighting in Yemen and the importance of ensuring that assistance can reach Yemenis on all sides of the conflict".
The United Nations has declared Yemen a level-3 humanitarian emergency, the highest on its scale.
More than 21.1 million people - over 80 per cent of Yemen's population - need aid, with 13 million facing food shortages, while access to water has become difficult for 9.4 million people.
The conflict has killed more than 3,200 people since late March, according to UN figures.
Firefighters work to extinguish fire following rocket attacks by Houthi rebels at storage tanks of an oil refinery in the port city of Aden.