Yemen's armed forces are claiming to have killed 43 suspected members of al-Qaeda in two days of air raids and shelling on their hideouts in the country's south.
The military had stepped up attacks against al-Qaeda in the mountainous area of al-Rahha in the province of Lahij, a strategically important region that links the south with Yemen's northern cities.
Military officials told the AP news agency that the government forces were trying to reclaim key cities in Aden and Abyan provinces in the south that have been overrun by al-Qaeda.
Sanaa-based journalist Mohammed al-Qadhi told Al Jazeera that al-Qaeda was exploiting the instability in the country following months of political unrest.
"Al-Qaeda (is) using the stalemate in the political process and the continued division of army and security forces ... to expand their activities in different southern provinces," al-Qadhi said.
Meanwhile, armed fighters have claimed responsibility for blowing up an oil pipeline in southern Yemen late on Monday in a second such attack in retaliation for a US drone strike that killed five suspected al-Qaeda members on Friday.
Yemen's oil and gas pipelines have been repeatedly sabotaged since anti-government protests broke out in January 2011.
Ansar al-Sharia, an armed group affiliated with al-Qaeda, said in a text message on Tuesday that the latest oil pipeline explosion was part of "a chain of attacks" planned in response to the US strike.
Al-Qaeda has strengthened its hold on southern areas of the Arabian Peninsula country, seizing several towns during the past year of protests against President Ali Abdullah Saleh, who left office in February 2012.