Yemen forces pressed on Sunday with an assault to recapture the Al-Qaeda-held southern city of Zinjibar, advancing on two fronts amid air cover in fighting that killed six soldiers in two days, military officials said.
The offensive takes place as US drones have intensified raids against Al-Qaeda militants in other parts of the country, killing 12 in two attacks on Saturday.
Four soldiers were killed in overnight fighting with militants around Zinjibar bringing the total of army losses since the all-out operation was launched Saturday to six, a military official said.
"The fighting continues and the army is advancing towards Zinjibar," the capital of the southern province of Abyan, said the official on condition of anonymity.
"The death toll among soldiers has increased to six, while 18 others were wounded," the official added.
He said that government forces have made progress on the southern and eastern fronts of the city, with troops reaching the Shaddad Fort, around three kilometres (1.8 miles) east of Zinjibar, and the Zinjibar Bridge, around one kilometre (0.6 miles) from the city.
Another military official said air raids on Sunday targeted Zinjibar and the neighbouring town of Jaar, while the artillery continued to pound the city.
The "wide offensive" began from three sides and was supported by the air force and the navy, a military official had said on Saturday, adding that Defence Minister Mohammed Nasser Ahmed was overseeing the operation.
"The defence minister is supervising a military plan to regain control of the city of Zinjibar and (the neighbouring town of) Jaar from Al-Qaeda gunmen," he said.
Six fighters of the Al-Qaeda-linked Partisans of Sharia (Islamic law), were also killed in the attack on Zinjibar, said a tribal source in Jaar, to where the gunmen evacuate their casualties.
Air strikes on Saturday also hit Jaar, killing three Al-Qaeda gunmen and a civilian, and wounding three civilians, a tribal source said.
The air raids were to pave the way for advancing ground troops, said a military official.
Military units also attacked Jaar from the west, a military official said on Saturday, adding troops had reached the area of Kadama, on the outskirts of the town.
The militants took advantage of a central government weakened by an Arab Spring-inspired uprising to overrun Zinjibar in May last year. They also control Jaar and other parts of the province.
Yemen's new president Abdrabuh Mansur Hadi, who was elected for an interim two-year term in a single candidate vote in late February, has pledged to rid Yemen of the extremist group.
Meanwhile, US drones killed 12 militants in two separate attacks on Saturday east of the capital Sanaa.
In the first raid, a drone targeted a vehicle carrying militants on the road linking Marib to Shabwa killing seven, a tribal chief said.
In the second attack, five militants were killed when two rockets hit two cars transporting them near the village of Al-Hosoon, outside Marib, a tribal chief and witnesses said.
An Egyptian and a Saudi were among the militants killed on Saturday, tribal chiefs said on Sunday.
Attacks on Al-Qaeda by Yemeni forces and suspected US drones have increased lately, including an air raid in eastern Yemen a week ago that killed jihadist network leader Fahd al-Quso, wanted by Washington in connection with the 2000 bombing of the USS Cole in Aden harbour.
Quso's name figured on an FBI list of most wanted terrorists, along with a reward of up to $5 million for information leading to his arrest.
US media reported that a Saudi spy, reportedly a "mole" or "double agent," spent weeks with Al-Qaeda in the Arabian Peninsula (AQAP) and garnered sensitive information that allowed the CIA to launch the drone strike against Quso.