Hundreds of earthquake victims in Pakistani Kashmir have acute diarrhoea and doctors are investigating whether they are cases of cholera, the World Health Organisation and the United Nations said.

Aid workers are urgently trying to improve water supplies and sanitation at the cramped refugee camps where the survivors fell sick in the devastated regional capital Muzaffarabad, WHO technical officer Rachel Lavy said.

"In one camp we visited yesterday, there were 55 cases of diarrhoea and there are so many spontaneous camps that we believe have hundreds of others," she said.

The UN has repeatedly warned it is racing against time and a shortage of international aid cash to prevent a possible second wave of deaths from disease, cold and hunger after the October 8 disaster.

More than 7,000 cases of diarrhoea - not all of them acute - and 8,000 cases of respiratory disease had been reported in the quake zone, a top Pakistani health ministry official said.

Acute diarrhoea can be fatal if it is not treated aggressively and immediately, Lavy said.

The earthquake is confirmed to have killed nearly 74,000 people in Pakistan and more than 1,300 in India. However humanitarian groups estimate the toll to be 86,000 in Pakistan.

Health workers said unsanitary condition in the camp in Muzaffarabad, which sprang up after the quake, had likely caused the outbreak. The workers were urgently giving rehydration salts and intravenous drips to the sick.

In Muzaffarabad, an ethnic-based group that set up a relief camp pulled out of the city following a clash between its supporters and a rival Islamic group that left two people injured.

PHOTO CAPTION

Indian Kashmiri residents arrive at the immigration office on the Pakistan side of the Line of Control near Kaman bridge in Chakhoti, Wednesday Nov. 9, 2005. (AP)