(CNN) — Al Qaeda militants seized control of a military base and two checkpoints during raids in southern Yemen on Monday in which at least 30 people died, security officials and residents said.

Hours of firefights erupted after the militants hit an army barracks in the Loder district of Abyan province in an assault that included heavy artillery, according to the officials.

The dead included 17 militants, 11 soldiers and two members of pro-government tribes, they said.

This is the second militant attempt to take over Loder this year. The first was in early January.

Last week, Yemen poured thousands of troops into the country’s south to battle al Qaeda fighters and tighten security, officials said. Yemeni warplanes bombarded al Qaeda hideouts all week in a series of U.S.-supported airstrikes in Abyan and Lahj provinces.

The offensive came after militants killed dozens of troops and seized large quantities of weapons when they raided a military zone. Numerous other Yemeni soldiers were taken hostage, officials said.

Yemen’s al Qaeda movement has expanded its control over parts of the country in the past year, leading politicians to consider the option of dialogue with the militant network.