He said the heavy shelling began overnight targeting the northeastern suburbs of Zinjibar, which jihadists have controlled since May following fierce fighting with government troops.

"Many bases of Al-Qaeda were destroyed," and 16 jihadists were killed, the official said on condition of anonymity.

The attacks were launched from the sea, he added.

Witnesses in the nearby town of Jaar said the bodies of 16 gunmen were buried in a makeshift graveyard in an ammunition factory. The corpses were torn to pieces.

Yemeni forces also launched air raids south of Jaar, another stronghold of Al-Qaeda, the official said.

Al-Qaeda militants have exploited the weakening central government in Sanaa to strengthen their presence in the country, especially across the restive south and southeast.

Zinjibar is the capital of Abyan province, a stronghold of the jihadists' local affiliate Al-Qaeda in the Arabian Peninsula, or AQAP, whose militants fight under the banner of Partisans of Sharia (Islamic law).

"We seek to engage meaningfully with the US on the basis of mutual interest and mutual respect", Asif Ali Zardari said in a televised address to parliament, describing the relationship as "multi-dimensional and important".

The joint session of Pakistan's parliament is tasked with reviewing and formally resetting the difficult ties with the US following what Zardari described as a "challenging year" in 2011.

The process is considered key to getting relations onto a more solid footing after US air strikes last November killed 24 Pakistani soldiers and brought the relationship to its lowest point in years.

The review is seen as a precursor to Pakistan reopening its Afghan land border to NATO convoys, which have been sealed since November 26, and a resumption of high-level American diplomatic visits.

We are looking forward to your recommendations for re-engaging with the United States," Zardari told parliament

The November 26 strikes capped a disastrous year for an alliance already seriously compromised by the covert raid to kill Osama bin Laden on May 2 and the detention of a CIA contractor who killed two Pakistanis in January 2011.

Islamabad closed its Afghan border and ordered US personnel to leave the Shamsi airbase, reportedly a hub for covert American drone strikes against the Taliban and Al-Qaeda in Pakistan's tribal belt.

Zardari also emphasised the "unique relationship" between Pakistan and China which he said was "deeply rooted and mutually beneficial".

"My eight visits to China are a manifestation of taking this relationship to new heights," he said.

China is the main arms supplier to Pakistan, which sees Beijing as an important counter-balance to its traditional rival India.

China meanwhile needs Islamabad's help in stemming potential terrorist threats in its far-western mainly Muslim region of Xinjiang, which borders Pakistan.