As many as 15,000 civilians have now fled al-Hota (Huta), the southern Yemeni town which has been besieged by the military since Sunday. 

Between 80 and 100 al-Qaeda militants are said to be holed up in the town (estimated population 20,000-25,000) and the surrounding area. It appears that the army has been shelling from a distance of 1-2km but is waiting for reinforcements before entering.

AFP says a tribal attempt at mediation to end the hostilities has been unsuccessful.

News Yemen reports that a tribal leader, Sheikh Abdel-Wahid Mansour, who was injured during clashes in the area on Saturday, has died in hospital. AFP suggests he was killed by militants.

There has been some speculation that the objective of the siege is to capture Anwar al-Awlaki, the wanted Yemeni-American preacher, but this has been officially denied. A spokesman for the Yemeni embassy in Washington says the military operation is in response to a recent attempted attack on a liquefied natural gas pipeline.

If this is the real reason, the military response seems extraordinarily disproportionate – unless the pipeline attack, which occurred on Monday last week, was a lot more serious than some reports at the time suggested.

Oil pipelines have often been attacked in Yemen but apparently this was the first attack directed at the LNG pipeline, on which the country is pinning a lot of economic hopes as oil production declines.

A Reuters report last week, quoting an unnamed official, describedthe attack as a failure: "The militants threw hand grenades which fell metres away from the pipeline and pumping was not affected." Dow Jones had a similar report, saying the damage was "minor".

However, Xinhua, the Chinese news agency, quoted a provincial police officer as saying a large number of bombs were used, causing a huge fire and cutting off the LNG supply.

Posted by Brian Whitaker, 22 September 2010.