Conflict in different parts of Afghanistan in the last week has driven tens of thousands of people away from their homes, the UN Office for the Coordination of Humanitarian Affairs (OCHA) said on Wednesday.

The office said that they are part of the nearly 390,000 people displaced by hostilities this year, with a massive spike since May. Many of the displaced fled to Kabul and other large cities, the Xinhua news agency reported.

Most of the displaced in the capital city are staying with families and friends, with a growing number camping in the open, facing increased vulnerability, it said. More than 5,800 internally displaced persons arriving in Kabul between July 1 and August 5 needed food, household items, water and sanitation support and other assistance.

Ten humanitarian teams on Wednesday assessed the needs of people staying outside in parks and other open spaces and identified an additional 4,522 displaced persons lacking shelter, food, sanitation and drinking water, OCHA said. A temporary health clinic and mobile health teams provided health services.

"Despite a worsening security situation, humanitarian agencies are staying and delivering to people in need, reaching 7.8 million people in the first six months of this year," OCHA said. "Some 156 non-governmental organizations and UN agencies have delivered assistance throughout Afghanistan."

While the humanitarians said they intend to stay despite increasing hostilities to deliver relief, it depends on staff safety, bureaucratic hurdles and raising additional funds.

The $1.3 billion Humanitarian Response Fund for Afghanistan is just 38 per cent funded, leaving an almost $800 million shortfall.