"Thirty-eight members of Al-Qaeda were killed in shelling and air strikes that targetted their positions in Huroor throughout the past 48 hours," said the official who spoke from the nearby Al-Qaeda stronghold of Jaar.
The town of Huroor lies on the crossroads between the provinces of Lahij and Abyan, where the terror network has a strong presence.
An army officer on ground told AFP that US forces backed the Yemeni military operation.
"The Al-Qaeda militants withdrew from Mallah," in Lahij, where they took over an army post on Saturday, "following shelling and air raids by the Yemeni air force with US help," he said, without elaborating.
On Saturday, at least 28 soldiers and 12 militants were killed in clashes that broke out in Lahij when the insurgents tried to take over several army posts.
Al-Qaeda's branch in Yemen, the self-proclaimed Partisans of Sharia (Islamic law), has exploited the decline in central government control that accompanied Arab Spring-inspired protests that eventually forced president Ali Abdullah Saleh to cede power.
Late Monday, a government official in the eastern region of Shabwa said saboteurs attacked an oil pipeline that runs from al-Alam, north of the provincial capital Ataq, to Al-Nasima near Belhaf.
In a text message sent to AFP, the Partisans claimed responsibility for the attack, the second of its kind this week.
"The mujahideen (holy fighters) blew up an oil pipeline in... Shabwa, as part of a chain of attacks to retaliate against the latest US raids on Azzan," it said, referring to a town where a US drone strike killed five suspected militants on Saturday.
The Islamists sabotaged a 320-kilometre (200-mile) gas pipeline linking Marib province to Belhaf terminal on the Gulf of Aden on Saturday.
Yemen LNG said "production has stopped but the loss of production is expected to be limited to four cargoes as the LNG Plant was due to shutdown on 15 April for annual maintenance."
In recent years, the US Defence Department has provided hundreds of millions of dollars worth of equipment and training designed to help Yemen's special forces counter Al-Qaeda.
The equipment has included aircraft, helicopters with night-vision cameras, sniper rifles, secure radios and bullet-proof jackets, according to the Congressional Research Service, a research arm of the US Congress.