RUSTAQ, Afghanistan (AP) _ Just when they thought aid was finally on the way, thousands of people left homeless by last week's earthquake in northeastern Afghanistan were dealt another cruel blow Friday.

High winds, snow and dense fog at the disaster site grounded a U.N. aircraft standing by in neighboring Pakistan with tons of desperately needed supplies.

Meanwhile, the United Nations and the international Red Cross said it might be days before they are able to begin parachuting supplies _ their best hope for reaching the remote mountainous region.

Nearly 5,000 people perished and thousands more are missing in the 6.1-magnitude earthquake, which split mountains and buried dozens of villages beneath rock and earth.

Yet more than a week later, relatively little aid has arrived, largely because roads that were already damaged from 20 years of war have been rendered virtually impassible by snow and mud.

``We're estimating that 30,000 people need help,'' said Sarah Russell, a spokesperson for the United Nations.

After four torturous days on the road, three U.N. trucks managed on Thursday to reach the regional center of Rustaq. Several tons of aid were also flown in, most of it blankets and plastic sheeting.

Refugees streamed to Rustaq from their ravaged mountain villages. Women clutched their burquas around their bodies to shield themselves against the wind. Men shoved to be in the front of crowds that besieged relief trucks.

Both the United Nations and the Red Cross had more convoys on the way in addition to the plans for an airlift.

The two organizations hope to parachute 1,000 tons of supplies into the region over one month, an operation they estimate will cost about $2.5 million.

But by late Friday they had received only $500,000 of that _ all in pledges from the United States, Sweden and Britain. As yet no country had come forward with the critical item, a cargo helicopter.

``Definitely air dropping is not organized in a couple of hours or even a couple of days,'' said Laurent Dufour, a Red Cross spokesman.

War has complicated relief efforts in the area, 100 miles north of the capital. The region is controlled by a military alliance fighting the Taliban government based in Kabul.

The Taliban, which controls about 85 percent of the country, offered $70,000 in aid today as well as rice and wheat, said Abdul Rehman Ottaqi, deputy information minister.

The Taliban has permitted international aid to cross its front lines.

``They are our brothers,'' Ottaqi said. ``This is a tragedy for all Afghans on both sides of the fight.''