The conflict in Syria has displaced more than two-thirds of Palestinian refugees living in the country, the UN Relief and Works Agency for Palestine refugees said on Wednesday.
"We have registered approximately 530,000 Palestinian refugees. We believe that almost all of them, certainly maybe 70-80 percent, are displaced from their normal homes," UNRWA Commissioner General Filippo Grandi told AFP on a visit to Syria.
Between 12 and 15 percent of the Palestinian refugee population has fled the country altogether, Grandi added.
"You can say that 12-15 percent of the refugee population in Syria is now (made) refugee again in another country," he said, speaking after meeting Palestinian refugees at a camp in central Homs province.
UNRWA has nine registered camps for Palestinian refugees in Syria, housing those who fled or were forced from their homes when the state of Israel was created in 1948, and their descendants.
Some of the camps, including Yarmuk in Damascus, have been the scene of heavy fighting in the conflict that began with peaceful anti-government demonstrations in March 2011.
Grandi said the Palestinians were neutral in the conflict, and urged both government forces and the rebels to respect the neutrality of the refugee population and their camps.
"I really want to appeal to the parties to this conflict, to the government, to the armed opposition groups, to respect the sanctity and the neutrality of the Palestinian refugee camps and not to involve the Palestinians in fighting," he said.
"The Palestinians are refugees in Syria and as such they must remain neutral. My appeal is also to the Palestinians themselves, they have to remain neutral, otherwise the situation, which is already very difficult, will become even more difficult."
Grandi also appealed for an end to kidnappings and arbitrary detentions, saying: "Every household, every family has a story to tell in this respect.
"I find this situation unacceptable and this is for Palestinians and for Syrians. This is a grave violation of human rights, whoever is perpetrating that violation. It must stop."
More than 90,000 people have been killed in the Syrian conflict, according to the Syrian Observatory for Human Rights watchdog.
There have been reports of Palestinians killed, as well as incidents in which refugees have joined the fighting, battling alongside either rebels or the regime.