Local officials in Yemen say at least five insurgents were killed in a government-led overnight assault in the city of Zinjibar, a city partly held by militants with ties to al-Qaeda, reported the Associated Press.

China's Xinhua news agency reported that the operation, part of the government's months-long campaign to regain full control of the city, involved gun battles and heavy fighting. 

More from GlobalPost: Yemen car bomb kills at least 26

Today's violence comes a day after a car bomb killed some 26 people in the southern city of Mukalla, just hours after the country's new president, President Abdrabbuh Mansour Hadi, took the oath of office. 

Al-Qaeda took responsibility for the attack, according to Reuters. 

Militants have moved into much of Yemen's south during the past year, taking advantage of the instability brought by a mass uprising against the government there.

The unrest prompted the resignation of President Ali Abdullah Saleh after 33 years in power.