* Clash and air attack see 11 militants, 5 soldiers killed
* Govt troops consolidate hold on Lawdar, govt says
ADEN, April 14 (Reuters) - At least 11 al Qaeda-linked militants were killed in clashes and an air strike in southern Yemen on Saturday, the Defence Ministry said on the sixth day of a government offensive which has killed about 200 people.
Yemeni air force planes destroyed a vehicle in the southern province of Bayda, killing three "leading al Qaeda terrorists", the ministry said on its website.
Ansar al-Sharia (Partisans of Islamic Law), a group affiliated with al Qaeda, said in a statement that three of its militants had been "martyred" in the attack which it said was carried out by a U.S. drone.
Meanwhile, outside the nearby port of Aden, militants opened fire on a checkpoint from two vehicles, prompting government troops to return fire, the ministry said. Eight militants and five soldiers were killed in the exchange of fire, it added. One of the militants' vehicles was also destroyed.
The deaths came as Yemen's military pressed ahead with an offensive against Islamist insurgents who attacked a military camp outside the southern city of Lawdar last week.
The ministry said troops were consolidating their gains in Lawdar on Saturday, flushing out pockets of militant resistance.
On Friday, at least 34 people, mostly Islamist militants, were killed near Lawdar, officials said, after the government intensified its operations, sending an elite anti-terrorism unit from the capital Sanaa to join the fight.
Ansar al-Sharia has repeatedly denied reports of government success in the fighting, and the killing of its leaders.
On Friday, it said in an emailed statement that its fighters had killed 37 tribesmen fighting for the government in the previous two days.
The conflict in the south is one of several challenges facing Abd-Rabbu Mansour Hadi, the new president.
Ansar al-Sharia seized a significant chunk of territory in the southern province of Abyan during the turmoil that led to the replacement of his predecessor President Ali Abdullah Saleh.
Hadi vowed to fight al Qaeda in a deal that eased Saleh from power. Saudi Arabia and the United States hoped the deal would prevent al Qaeda getting a foothold near key oil shipping routes in the Red Sea.
Washington, which has pursued a campaign of assassination by drones and missiles against alleged al Qaeda targets in Yemen, wants him to reunify a military that is split between Saleh's foes and allies, and direct its efforts at "counter-terrorism.
Hadi also faces challenges from Shi'ite Muslim rebels in the north and southern secessionists. (Reporting by Mohammed Mukhashaf in Aden and Mohammed Ghobari in Sanaa; Writing by Firouz Sedarat; Editing by Andrew Osborn)