Dozens of unidentified gunmen have captured a Yemeni army compound in the southeast of the Arabian peninsula country, a military official said.
At least three soldiers were killed and six others wounded in the fighting on Monday as the attackers wrested control of the army compound in the port city of al-Mukalla.
Officials said the gunmen were since holding an unknown number of soldiers hostage.
"Some of the attackers managed to infiltrate into the base," the official said.
They caused confusion because soldiers at the base thought they were being attacked by members of the Central Security apparatus
"They caused confusion because soldiers at the base thought they were being attacked by members of the Central Security apparatus."
Witnesses told Al Jazeera the unidentified gunmen were dressed in special forces uniforms and drew up in four military vehicles, stormed the compound taking many more soldiers hostage. Security officials allege the gunmen were suspected al-Qaeda fighters, though local sources said the fighters were more likely soldiers and the fighting was part of a feud between two army units.
There have been problems between two army units over the last two years in Mukalla and this incident might be part of this feud, sources said.
The commander of the army's second military region, General Muhsen Hasan, was in the building at the time of the attack, and is thought to have been captured.
Army reinforcements have been deployed to the area and have engaged the rebels, the official said, warning that the gunmen would "pay a heavy price" for the attack.
Mukalla is capital of Yemen's southeastern province of Hadramawt and a major port city.
It is the second major assault on the Yemeni army in 10 days blamed on al-Qaeda in 10 days.
Mukalla is the capital of Yemen's southeastern province of Hadramawt and a major port city.
On September 20, suspected al-Qaeda fighters killed at least 56 soldiers and police in coordinated dawn attacks in Shabwa province further west.
That was the deadliest day for the Yemeni security forces since the army recaptured a string of southern towns from the jihadists in a major offensive last year.
Washington regards al-Qaeda in the Arabian Peninsula as the most dangerous affiliate and has stepped up its drone strikes against the group in recent weeks.