Up to 15,000 flee offensive in Yemen's Shabwa province
As many as 15,000 Yemeni civilians have fled their homes as the government pursues a new offensive against rebels in the country's South, officials say.
The fighting is focused on the town of Huta, in the mountainous Shabwa region, where Yemeni forces have said up to 100 suspected al-Qaeda fighters are hiding.
Almost all the town's residents have reportedly fled from deadly clashes that have been raging since Sunday.
The fighting comes during a visit by a top US counter-terrorism official.
Presidential advisor John Brennan is in the country to discuss a military aid package reported to be worth more than $1bn (£640m) over the next five years.
The US stepping up its training, intelligence and military aid to the country following a failed plot to blow up a US plane last December, for which the Yemeni wing of al-Qaeda claimed responsibility.
But many Yemenis believe aid money could be better spent on improving the lives of ordinary people in one of the poorest countries in the Middle East, says the BBC's correspondent in the region, Jon Leyne.
Earlier reports said three militants and two soldiers have died in the clashes.
"The siege will remain until those elements hand themselves in and we manage to uproot terrorist groups from the region," said provincial governor Ali Hassan al-Ahmadi, according to the AP news agency.
Reports from the area say the displaced civilians have received little or no humanitarian aid.
Shabwa is the home province and suspected hiding place of the radical Muslim cleric, Anwar al-Awlaki, a US-Yemeni citizen who is wanted by the US authorities for his links to al-Qaeda.
Al-Qaeda in the Arabian Peninsula (AQAP) has established strongholds in the country's largely autonomous tribal regions, analysts say.
The group has been responsible for a number of deadly attacks in Yemen, including a raid on the country's domestic intelligence agency in Aden in June, in which 13 people died.