* Al Qaeda militant from Uzbekistan among 7 killed
* Third day of army offensive to eradicate Yemen's al Qaeda
* Local media says army meeting stiff resistance (Adds AQAP cell leader killed)
By Mohammed Mukhashaf
ADEN, Yemen, May 1 (Reuters) - Government troops killed an al Qaeda commander from Uzbekistan and six other fighters in a battle in south Yemen on Thursday, the third day of a military offensive against the Islamist group, a local military source said.
The Uzbek citizen, known as Abu Muslim al-Uzbeki, died during fighting in the province of Abyan, the source told Reuters. Two days ago, President Abd Rabbu Mansour Hadi said 70 percent of al Qaeda fighters in Yemen were foreigners.
Al Qaeda in the Arabian Peninsula (AQAP) and its off-shoot Ansar al-Sharia have hampered the U.S.-allied country's efforts to restore stability since a revolt in 2011 that forced a change in government.
Hundreds of people have died in bombings, suicide attacks and raids by the militant group against military and government facilities and foreign nationals.
Stability in Yemen, which shares a long border with the world's top oil exporter Saudi Arabia, became an international concern in recent years after AQAP tried to carry out attacks abroad, including an attempt blow up a U.S.-bound plane.
Since 2012, AQAP's main base has been Abyan's mountainous al-Mahfad area, where militants fled after the army, with U.S. help, drove them from towns and areas they had seized during the chaotic uprising against then-President Ali Abdullah Saleh.
Yemeni troops began their offensive on al-Mahfad, which spans 20,000 square kms (7,700 square miles), on Tuesday, backed by air force planes and hundreds of local militiamen.
A Yemeni official and a tribal source told Reuters that the head of the AQAP cell in al-Mahfad had died.
The tribal source said the cell leader, known as Ali bin Lakraa', had died of wounds inflicted during air strikes that targeted the militants' training camps in Mahfad earlier this month.
"His cell was the most active of AQAP and Ansar al-Shariah in Yemen. That cell launched multiple operations that targeted the military and oil and gas facilities," the official said.
A local source described him as "one of the most high profile and active al Qaeda leaders in Abyan and Shabwa provinces".
State news agency Saba said on Thursday that the army had directed "painful blows" to militants in al-Mahfad. The battle was being overseen by the defence minister himself, it said.
According to Saba, the governor of the southern al-Bayda province and the head of the southern military command survived an ambush on Thursday, but three of his guards were killed.
So far around 12 al Qaeda fighters and five Yemeni soldiers have been killed, according to local officials and state media.
However, independent media outlets from south Yemen suggest the army is encountering stiff resistance from militants and is suffering heavier losses than the government is ready to admit.
The Aden al-Ghad newspaper described the fighting near al-Mahfad as "vicious" and published what it said were exclusive photos of burnt-out of armoured vehicles. (Additional reporting Mohamed Ghobari in Sanaa and Yara Bayoumy in Dubai; Writing by Reem Shamseddine and Yara Bayoumy; Editing by Sami Aboudi and Raissa Kasolowsky)