More than 100 Yemeni soldiers and at least 25 suspected Al-Qaeda gunmen were killed in attacks on military positions in the country’s restive south.

More than 100 Yemeni soldiers and at least 25 suspected Al-Qaeda gunmen were killed in attacks on military positions in the country's restive south, medics and local officials said on Monday.

Sunday's assault was one of the single deadliest against Yemeni troops and the latest in a spate of attacks on security forces since President Abdrabuh Mansur Hadi pledged to crack down on the militants in an inauguration speech last month.

A medical official at the military hospital in the southern port city of Aden, who spoke on condition of anonymity, said "the death toll... has risen to at least 103" soldiers.

He said "many soldiers died from wounds sustained in the assault" on army posts on the outskirts of Zinjibar, Abyan's provincial capital where Al-Qaeda linked militants are in control.

Military officials had reported fierce clashes Sunday when suspected Al-Qaeda militants tried to overrun an army post in Kud, just south of Zinjibar. The violence then spread to other military positions on the outskirts of the city.

At least 25 Al-Qaeda gunmen were killed in Sunday's fighting and several others wounded, a local official from the nearby militant stronghold of Jaar told AFP.

He also said at least 56 soldiers were captured by Al-Qaeda, including seven army officers and 10 wounded soldiers.

The militants, known in Yemen as the Partisans of Sharia, seized control of Zinjibar and several other towns in Yemen's mostly lawless south last May as former president Ali Abdullah Saleh faced mass anti-regime protests.

Hundreds of Jaar's residents have fled over the past two days for fear that clashes between the army and Al-Qaeda could spread to their town, a government official there said.

The military official, who was at the scene during Sunday's attack, said troops from the Kud base were "surprised" to see the militants carrying army issue weapons and using military vehicles.

Soldiers who survived the attack accused some army leaders who had served under Saleh of "collaborating" with Al-Qaeda.

On Monday, unknown gunmen opened fire at the police chief of Sheikh Osman neighborhood of Aden, Colonel Abdullah al-Mawzaie, wounding him and a companion as they headed towards the southern province of Lahij, a security official said.

The violence highlights the security challenges facing Yemen's new president as he tries to restore order and unify the country's armed forces, as stipulated by a Gulf-brokered transition accord that ended Saleh's 33-year rule over Yemen.