UNITED NATIONS - Aid agencies have urged the warring parties in South Waziristan to observe international humanitarian law ensuring safety for civilians, the United Nations humanitarian arm said on Sunday. To date around 139,000 people have fled the conflict in the South Waziristan region into the bordering North West Frontier Province (NWFP), according to the UN Office for the Coordination of Humanitarian Affairs (OCHA). Those leaving South Waziristan have travelled over a forbidding terrain, with limited supplies and in conditions of fear and hardship, said UN Humanitarian Coordinator for Pakistan Martin Mogwanja. As displaced civilians reach areas of relative safety, the United Nations and its humanitarian partners are working to make sure that they have the support - even simple necessities, from food and water to blankets and health protecting vaccines - to weather this terrible time, added Mr Mogwanja. The OCHA said that the humanitarian community in Pakistan calls upon the combatants to respect humanitarian law and its principles of distinction between civilians and combatants, as well as proportionality in the means and methods of warfare. Underscoring that attacks on civilians are absolutely prohibited and that civilians have to be granted safety and safe passage, OCHA highlighted the need to ensure the continuation of assistance. The UN and its partners have been providing aid in the form of registration to assess the numbers and needs of the internally displaced persons (IDPs), food rations, vaccination for children, household items and hygiene kits, and access to drinking water. In the last 10 days alone, 57,600 IDPs have been registered in two NWFP districts - Dera Ismail Khan and Tank. Most of the IDPs are taking shelter in host communities, with friends and families, or in rented homes, following a pattern set in other recent conflicts in Pakistan. At present, no camps have been set up in the two hosting districts, but the humanitarian community stands ready to assist with tents, sanitation and other facilities if needed. As international aid organisations have no direct access to the conflict areas in South Waziristan, humanitarian assistance is delivered through local partners in Dera Ismail Khan and Tank. UN agencies and their partners have distributed over 1,000 tons of food to around 30,000 people, while 35,000 have received hygiene kits to prevent the spread of disease in these difficult, congested conditions. Agencies have also rehabilitated water supplies and installed hand pumps, ensuring that 45,000 IDPs have access to safe water. Many of the children have never been vaccinated, and measles immunisation campaigns have already reached over 180,000 children, both from IDP and host community families, OCHA said.