Several protesters were injured and several arrested.
The violence broke out on Friday as about 200 people marched through a street in central Muzaffarabad, the capital of Pakistan-administered Kashmir, which bore the brunt of the magnitude 7.6 quake.
About 50 policemen blocked their way, then began dispersing the crowd with rifle butts and canes. Among those injured was a man left lying by the roadside.
Several men were taken away in police vehicles.
Earthquake survivors have been setting up informal camps all over the city, most of them lacking adequate sanitation and considered to constitute a public health risk.
The quake, centred in Kashmir, killed about 86,000 people in Pakistani territory and another 1350 in India, destroying bridges, roads and the homes of many more.
Relief workers fear that as many people will die of hunger and exposure during the bitter winter.
Winter will descend in a couple of weeks. By then, about three million people will have to find shelter, with food stockpiled to see them through to spring.
It is an operation that experts say is more difficult than that which followed last year's Indian Ocean tsunami, a catastrophe which prompted a torrent of aid.
However, all but a small amount of the money pledged at the UN conference in Geneva late last month was meant for reconstructing the flattened villages of Pakistani Kashmir and neighbouring North West Frontier Province.
"It's a little bit frustrating, to tell you the truth," said World Food Programme spokesman Khaled Mansour.
"Compared with other crises of the same magnitude, this is more complex in terms of logistics and the response of donors has definitely been disappointing"
World Food Programme spokesman
"Compared with other crises of the same magnitude, this is more complex in terms of logistics and the response of donors has definitely been disappointing."
Starting on reconstruction work is months away.
"It is, in my view, not right to sit with reconstruction money for one year from now if we are not sure whether those people will be alive one year from now," UN aid chief Jan Egeland said in Geneva.
Some UN agencies had run out of cash, Egeland said after a conference preceded by a clamour of complaints that the world was not helping enough.