The killing of two Lebanese Red Cross workers at the Naher el-Bared Palestinian refugee camp on Monday threatens the already fragile lifeline to thousands of civilians still trapped there, World Vision has stated.

"Since the fighting started one month ago, World Vision has called on all parties to distinguish between combatants and civilians and to ensure neutral and impartial access to aid distribution," said advocacy manager Patricio Cuevas-Parra. "This incident is a clear violation of internationally accepted principles that protect humanitarian workers who deliver aid in a crisis. All parties must ensure safe humanitarian access for aid workers."

3,000-5,000 people remain inside Naher el-Bared camp, which is located near Tripoli in North Lebanon, the United Nations estimates.

"Whether this was an accident or a deliberate attack, this incident may threaten the well-being of those civilians who are unable to leave Naher el-Bared," said Cuevas-Parra.

More than 29,000 Palestinian refugees have fled their homes in Naher el-Bared. Approximately 25,000 have crammed into the nearby Beddawi Palestinian refugee camp where they have taken refuge in crowded schools and squeezed into tiny apartments with friends and relatives.

Since the fighting, World Vision has delivered nearly 4,500 baby hygiene kits containing nappies, baby wipes, water sterilisation tablets and other critical items to protect the health of the youngest and most vulnerable displaced Palestinian refugees in the Beddawi, Bourj el-Barajneh, Shatila and el-Buss Palestinian refugee camps, as well as in the Bekaa Valley.

The international relief agency has also distributed 150 baby cots and sets of baby clothes to women with infants or who are pregnant and expect to deliver soon in the Beddawi camp. Sixty more cribs will be distributed Thursday to the Bourj el-Barajneh and Shatila camps, where smaller numbers of displaced refugees have moved.

In addition, World Vision is supporting the creation of child friendly spaces with other local and international partners by providing five tents and recreation kits to partners who are organising the activities.