ADEN (AFP) ― Yemeni forces on Sunday pressed an assault to recapture the al-Qaida-held southern city of Zinjibar, as U.S. drones intensified raids against the jihadists in other parts of the violence-wracked country.

The battles against the militants were being carried out with “U.S. logistical support,” a military official said, as state news agency Saba reported that John Brennan, U.S. President Barack Obama’s top counter-terrorism aide, held talks in Sanaa Sunday with Yemeni President Abdrabuh Mansur Hadi.

The report said that discussions had revolved around “combatting terrorism” and the attempts by the army to subdue the Yemeni branch of al-Qaida, believed to behind a new plot to blow up a U.S. airliner.

In a message to Obama, Hadi told Brennan that “hunting terrorists is an irreversible decision and they will be pursued until these regions are cleansed from their presence.”

According to the Yemen military official, who spoke on condition of anonymity, 12 soldiers have been killed since the all-out operation against al-Qaida was launched around Zinjibar, capital of Abyan province, on Saturday.

“The fighting continues and the army is advancing towards Zinjibar,” the official said, adding that government forces had reached the Shaddad Fort, around three kilometers east of Zinjibar, and Zinjibar Bridge, just one kilometer from the city.

Another military official said air raids on Sunday targeted Zinjibar and the neighbouring town of Jaar, while 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-Qaida gunmen,” he said.

Six fighters of the al-Qaida-linked Partisans of Sharia (Islamic law), were 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-Qaida gunmen and a civilian, and wounding three civilians, a tribal source said.

After the air raids, military units attacked Jaar from the west, reaching 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.

Hadi, who was elected president for an interim two-year term in a single candidate vote in late February, has pledged to rid Yemen of the extremist group.

As the battles for Zinjibar and Jaar were raging on Saturday, U.S. drones killed 12 militants in two separate attacks 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.

Attacks on al-Qaida by Yemeni forces and suspected U.S. drones have intensified, 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 harbor.

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.

U.S. media reported that a Saudi spy, reportedly a “mole” or “double agent,” spent weeks with al-Qaida in the Arabian Peninsula (AQAP) and garnered sensitive information that allowed the CIA to launch the drone strike against Quso.

A senior U.S. official told the New York Times the spy had also revealed plans by AQAP to blow up a U.S. airliner using a bomb sewn into “custom fit” underwear that would have been difficult to detect even in a pat-down at an airport.