The first major test of President Obama's troop surge strategy, it targets Marjah district, the Taliban's last big stronghold in Helmand province.

British and Afghan forces are also involved in the operation to impose government control on rebel-held areas. Hundreds of families from Marjah have sought refuge in nearby Lashkar Gah. Many said Taliban leaders had tried to prevent them leaving and that they were forced to flee under cover.

"We were not allowed to come here," said Marjah resident Bibi Gull, after arriving in Lashkar Gah.
"We have not brought any of our belongings. We just tried to get ourselves out of there. Three of my sons are still in the village and the other three have come with me."

Unlike previous military operations, the assault on Marjah had been widely flagged in the hope many fighters would lay down their arms or flee. Most of the population has stayed put, raising fears civilians could get caught up in the fighting.

 euronews