Dozens of people have been killed in heavy fighting between the army and suspected al-Qaeda linked fighters in Yemen's southern province of Lahij, officials said.
"Seventeen soldiers were killed in the fighting", which erupted when fighters attacked army positions in al-Mallah, a town in Lahij province, an army officer on the ground told AFP news agency.
Thirteen armed fighters were also reported to have been killed.
Mohammed al-Qadhi, a reporter with Abu Dhabi's The National newspaper, told Al Jazeera from Sanaa: "The militants, which are controlling some parts of the southern province of Abjan, have attacked a nearby province called Lahij.
"They made a surprise attack on a military base there and they tried to control this but the army fought back and they have called the air jets to intervene and they were able to push them outside the base.
"This fighting has come hours after the militants claimed responsibility for the attack on a gas pipeline in the southern province of Shabwa and this attack on the pipeline came after US drones carried out strikes yesterday on the militants, killing six of them," al-Qadhi added.
Al-Mallah is adjacent to Abyan province, another suspected al-Qaeda linked stronghold.
A military official told AFP "two army tanks and three al-Qaeda vehicles were destroyed in the fighting, [while] al-Qaeda militants have seized several soldiers."
The attackers targeted the 119th and 201st army brigades, involved in military operations aimed at regaining control over Zinjibar, the capital of Abyan province southeast of Lahij, which the fighters overran last May.
On Friday, al-Qaeda members sabotaged a 320km gas pipeline linking Marib province to Balhaf terminal on the Gulf of Aden, all in the country's restive south.
The pipeline attack came shortly after two US drone attacks in eastern Yemen targeted Al-Qaeda suspects.
Fighters have seized on the political and security turmoil following Yemen's year-long uprising and have taken control of several towns in the south.