U.S. war planes carried out heavy strikes Thursday against Taleban positions near the Tajikistan border. More strikes are reported against Taleban frontline positions north of Kabul.

Thursday's strikes against Taleban positions in northeast Afghanistan mark the eighth time in 12 days that U.S. bombers have pounded Taleban frontlines near Mazar-e-Sharif. Pentagon officials say about 80 percent of their air strikes against targets in Afghanistan are now concentrated on helping the Northern Alliance break through the Taleban lines around the city.

There are conflicting reports about the extent of gains being made by the Northern Alliance. Alliance commanders say they have captured several key crossroads south of Mazar-e-Sharif, but Taleban authorities say they have pushed the Alliance troops back. Pentagon officials describe the situation around the city as fluid.

Whoever controls Mazar-e-Sharif controls land routes to Uzbekistan and Tajikistan as well as the main road south to Kabul. Heavy snowfall is already reported in some parts of northern Afghanistan, which some military analysts say could slow down the Northern Alliance offensive.

The Afghan winter is also a cause for concern for aid officials. The U.N.'s World Food Program says it might have to begin food air drops in northern Afghanistan if heavy snows block land routes. Khaled Mansour a WFP spokesman in Islamabad says many lives are at risk.

"North Afghanistan, as it has been a few times before, is the hunger belt of Afghanistan," he explains. "The World Food Program is seeking to help about three-million people stay alive until the harvest mid-summer next year."

The WFP says it used two cargo aircraft to carry 2,000 tons of food aid to Turkmenistan where it will be transported over land to northern Afghanistan.