Ten Yemeni soldiers and 18 suspected Al-Qaeda militants were killed Wednesday in confrontations in three provinces, security officials and the defence ministry said.
Five soldiers were killed in an ambush in the southern province of Shabwa in the third attack of its kind this month blamed by security officials on the jihadists.
"Gunmen probably belonging to Al-Qaeda opened fire on an army vehicle in Habban in Shabwa province, killing five soldiers and wounding another," a security official said.
He added that the attackers then escaped.
Meanwhile, two soldiers were killed and two wounded in a clash with gunmen in Sayun, in the southeastern Hadramawt province, another security official said.
The official said the "Qaeda gunmen" confronted forces from the 135th Armoured Brigade on their way towards the city, which is a stronghold of Al-Qaeda.
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The army is reinforcing its presence on the outskirts of Sayun in preparation for an imminent operation against militants, the official said.
The defence ministry said "18 members of Al-Qaeda" were killed in this confrontation, adding that several others were captured, including a Saudi.
Assailants suspected of belonging to Al-Qaeda also shot dead three members of the interior ministry's Special Forces in an ambush in Rada, in the central Baida province, a security official said.
Six other personnel were wounded, he said.
On Monday, four soldiers died in a ambushes in Hadramawt, and four policemen were killed on Saturday in an attack on a checkpoint in Shabwa.
Security services also blamed the two earlier attacks on Al-Qaeda in the Arabian Peninsula, which has been branded by Washington as the extremist network's deadliest franchise.
In late April, the army launched a ground offensive against AQAP in Shabwa and nearby Abyan provinces.
The group is active across several parts of Yemen, taking advantage of a collapse of central authority during a 2011 uprising that ousted veteran president Ali Abdullah Saleh.