Lebanon-Leading aid agency CARE International is calling for a safe corridor in Lebanon to deliver aid to the most at risk.
Without safe access to aid, up to 5,000 refugees are trapped in camps without electricity or clean water, CARE warned.
Harriet Dodd , CARE's Country Director for Jordan, who is overseeing CARE's work in Lebanon, said: "Many of those trapped are believed to be the elderly, sick, handicapped and injured.
"We are very concerned for the survival of these people if no safe corridor to deliver humanitarian assistance is secured immediately. Refugee families many of whom have young children were poor before they fled and are seeking refuge in already the crowded and impoverished environments that are typical of Palestinian camps in Lebanon. This is both an issue for immediate assistance and long term review of the conditions in which they live."
CARE is providing aid to civilians caught in an ongoing confrontation between the Lebanese Army and militants of the Fatah al-Islam faction.
CARE is primarily moving supplies to civilians displaced by the fighting, and is concerned with opening up humanitarian access to up to 5,000 people still trapped in the Naher al-Bared refugee camp which is home to 28,000 Palestinian refugees. Electricity to the camp stopped when the fighting broke out, and much of the camp's water system was damaged. Continued fighting has made getting food and water into the camp hazardous, and with garbage piling up inside the camp there is danger of an outbreak of disease.
Working in close coordination with UNRWA - the UN Relief and Works Agency working with Palestinian refugees - and other local agencies, CARE is providing mattresses and bedding for 3,000 of the displaced.
Fighting between Lebanese Army and Fatah al-Islam erupted on May 20, after Lebanese authorities tried to arrest suspects in a bank robbery. The fighting quickly escalated and spread to the Naher al-Bared refugee camp. An estimated 23,000 people have fled the camp. Some 16,000 have found temporary shelter in a neighboring refugee camp, Al Bedawi, while another 3,000 have gone to Tripoli and 4,000 have gone further to Beirut and camps in the South nearby areas.