Tribal elders pleaded for NATO to finish the operation quickly and spare civilians — an appeal that offers some hope the townspeople will cooperate with Afghan and international forces once the Taleban are gone.

Thousands of US and Afghan troops have ringed the town of Marjah in Helmand province, poised to enter the farming community, drive off the Taleban and restore government control over a major insurgent supply base and opium-poppy center 610 km southwest of Kabul.

Once the town is secured, NATO hopes to rush in aid and restore public services in a bid to win support among the estimated 125,000 people who live in Marjah and surrounding villages.

Although the Marjah operation began weeks ago with the movement of troops, US commanders have not revealed when the main attack will take place. They have signaled their intention to attack Marjah for weeks in hopes that civilians would seek shelter.

The operation, which is under NATO auspices, is the first major offensive since President Barack Obama announced last December that he was sending 30,000 reinforcements to Afghanistan, and will serve as a significant test of the new US strategy for turning back the Taleban.

Residents told The Associated Press by telephone this week that Taleban fighters were preventing them from leaving, warning the roads were planted with land mines to slow the NATO advance.

Nevertheless, the road between Marjah and the provincial capital of Lashkar Gah, 30 km to the northeast, was jammed Friday with hundreds of cars and trucks filled with people fleeing ahead of the assault.

Many said they had to leave quickly and secretly to avoid recrimination from Taleban commanders.

Some said they slipped out of town when Taleban commanders weren't watching. “We were not allowed to come here. We haven't brought any of our belongings; we just tried to get ourselves out,” said Bibi Gul, an elderly woman in a black headscarf who arrived in Lashkar Gah with three of her sons. She left three more sons behind in Marjah.

Police searched the vehicles for any signs of militants, in one case prodding bales of cotton with a metal rod in search of hidden weapons.

“They don't allow families to leave,” Marjah resident Qari Mohammad Nabi said of the Taleban. “The families can only leave the village when they are not seen leaving.”