"Everyone is looking to the sky and waiting and thinking when will the American aircraft come and starting killing them."
Even before the American strikes, Pakistan was sheltering some 2.5 million Afghans who had fled years of civil war and drought. It says it cannot cope with any more.
Click here for a map of Afghanistan's battle lines
Pakistani officials say 50,000 Afghans have crossed into Pakistan since the crisis began.
UNHCR chief Ruud Lubbers warned on Friday that hundreds of thousands of Afghan refugees will need urgent help in the coming weeks.
Mr Lubbers said that his agency had prepared camps on the border with Pakistan, which could deal with up to 300,000 people.
But he said this figure was sure to rise steeply.
Two thousand of the refugees are still stranded in Chaman, about 130 km (80 miles) from the Taleban stronghold of Kandahar.
The UNHCR is to ask Pakistan to allow them to deliver emergency supplies to the area.
The UN is painting an increasingly bleak picture of the fate of the refugees.
Many Afghans, they say, have not got money for food, let alone the journey to the border.
Grim future
New arrivals report having to pay smugglers up to $50 - a huge sum in a country already brought to its knees by drought and war.
Most Afghans know by now that the border with Pakistan - and those with Iran and Central Asia - are all officially closed.
Refugees speak of people fleeing to rural areas - leaving behind half empty cities and adding to the million people the UN estimated were already displaced within Afghanistan before the crisis.
But even inside Pakistan, the refugees face a grim future.
The Pakistani Government is only allowing new refugee camps to be built in the border area, a remote and inhospitable region.
Aid agencies have pleaded with the government to be allowed to build camps elsewhere.
They say their work is frequently hampered by attacks on their staff in an area that is notoriously insecure.
Moreover, the area lacks much basic infrastructure making it harder to supply essentials such as water - all this when the region is suffering a drought.