Yemeni security forces killed 18 suspected members of al-Qaeda over three days in a massive crackdown in the southern town of Loudar, police sources said on Monday, dpa reported.
The Interior Ministry said in a statement that four members of al- Qaeda were killed after police clashed with militants in the mountainous town of Abyan province on Monday.
Monday's fatalities bring the death toll of suspected al-Qaeda members to 18 since the operation began on Saturday. Fourteen other suspects were killed in clashes on Saturday and Sunday, security officials said.
The ministry said police raided houses where al-Qaeda militants and armed men believed to be loyal to the separatist Southern Movement were hiding in the town of about 100,000 inhabitants.
It said police were also pursuing injured suspects who were evacuated by fellow militants and who might seek treatment in hospitals in Abyan and the neighbouring provinces of Shabwa and al- Baiydha.
Police seized RPG launchers, assault rifles, hand grenades and ammunition during the raids, the ministry said, adding that some of the gunmen managed to flee the besieged town.
The Defence Ministry accused members of the Southern Movement of backing al-Qaeda militants, saying in a statement that members of the separatist movement are holed up with the militants in some houses in Loudar.
Loudar is located nearly 550 kilometres south of the capital Sana'a, and is close to the Hatat mountains where militants from al- Qaeda and Islamist groups are believed to frequently take shelter.
A police official told the German Press Agency dpa that local authorities have evacuated residents to schools and temporary shelters to prevent civilian casualties.
"A house-to-house search is underway, and the campaign will not stop until the town is cleaned of those elements," the official, who requested anonymity, said by phone from Zenjibar, the provincial capital of Abyan.
He said about 200 al-Qaeda militants were hiding in the town, including at least five Saudis.
The clampdown was triggered by an ambush by suspected members of al-Qaeda on an armoured police vehicle in Loudar that left 11 policemen dead on Friday.
It follows a string of attacks by al-Qaeda that targeted security personnel in southern Yemen in the past two months.
The group claimed responsibility for five attacks in June and July, including one on the headquarters of the intelligence services in the southern port city of Aden that left 11 dead on June 19.