Thousands were feared dead yesterday after northern Afghanistan was devastated by the second earthquake since February.
"The destruction was quite amazing," the United Nations Co-ordinator for Afghanistan, Mr Alfredo WitschiCestari, said on return from Shar-iBuzurg, the most seriously affected area.
"We saw a couple of villages that had been completely flattened, but there are probably more.
"This is a mountainous region and the force of the earthquake sent houses crashing down hillsides towards the valley below," he said.
Aid workers said up to 3,000 people were killed when the earthquake. An anti-Taliban alliance in the region and the Taliban, a fundamentalist Islamic group which controls most of Afghanistan, said 5,000 died.
The UN said the population of the entire region was thought to be 60,000 and that half of these lost their homes.
The earthquake, measuring 7.1 on the Richter scale, struck on Saturday.
The Taliban swept to power after seizing the capital, Kabul, in September 1996, but its opponents still control parts of the north.
"Now we have confirmed information from our colleagues and other aid workers in Takhar that 3,000 people have died in yesterday's quake," Mr Chris Teirlinck of the relief agency Medecins Sans Frontieres said from the northern Afghan city of Mazar-i-Sharif.
Aid agencies are still in northern Afghanistan since February's quake, which killed 4,000.
International aid workers beat hostile weather and began arriving late yesterday afternoon in Faizabad, to the east of the epicentre of the quake.
One plane belonging to the International Committee of the Red Cross (ICRC) carrying medicine and 12 relief workers managed to land in Faizabad after the clouds cleared.
"We attempted this morning and failed to land, but the weather cleared and the second time our plane landed in Faizabad early afternoon." Mr Juan Martinez, a spokesman for the ICRC said.
"We had 12 people on board to assess the situation and 400 kg of medicines with war-wounded sets." he said.
Mr Martinez said the death toll could be higher than 3,000 and that his organisation would send more planes in coming days.
"It is possible because the quake was strong. It will take a few days to confirm the casualties," he told Kabul reporters.
The United Nations said that a UN team also reached Faizabad to assess damage to the three worst-affected areas - Shar-i-Buzurg, Rustaq and Chah-ab.
Rustaq bore the brunt of February's quake, measuring 6.1 on the Richter scale, in which 14 villages were demolished.
"It takes five days to reach Shar-iBuzurg from the nearest town, Faizabad, by horse or donkey. There are no roads linking the region to the outside world," the UN said in a statement.
"The UN is preparing to fly tents and blankets to the region to meet immediate shelter requirements. Other key needs are likely to be water and food, as well as medical supplies."
Mr Teirlinck said aid workers from parts of the afflicted Takhar province had now reached the quake-hit region.
"Over 36 villages have been destroyed in Takhar province and relief workers now say that 21 villages have been destroyed in Badakhshan [province] too," he said quoting aid workers from the scene of the disaster.
Relief workers said low cloud, rain and mist were hampering assessment operations in the region, which lies along the Afghan border with Tajikistan.
More tremors were felt yesterday in Takhar province, aid workers and residents said. Mr Teirlinck said that the biggest problem now in the region was lack of medicine.