Sanaa, Yemen (CNN) -- Yemeni troops raided a third al Qaeda stronghold in a southern province, killing 40 suspected militants, authorities said Friday.
The troops entered Shaqra town in Abyan province.
Militant leaders fled, leaving behind large caches of heavy artillery, according to two security officials who did not want to be named because they are not authorized to talk to the media.
Most of the town is under government control, and troops have surrounded militants and given them a deadline to surrender, the defense ministry said.
The operation comes three days after government troops retook Jaar and Zinjibar towns from the militants. Government forces killed more than 80 militants during the operation in the same province, the officials said. .
Most of the militants have been forced to find safe havens amid an escalated crackdown, said Ahmed al-Ashwal, the Yemeni chief of staff.
Militants are trying to regroup In Azzan, an al Qaeda-controlled town in neighboring Shabwa province, officials said. Clashes with troops there Thursday killed 17 militants, three local security officials said.
The clashes are inching closer to Balhaf, home of Yemen's strategic gas and shipping port.
Yemen is intensifying its fight against al Qaeda after a year-long political crisis allowed the militant group to seize large areas in the south.
President Abdurabu Hadi has said fighting the terror network is the nation's highest priority.