The United Nations has called for immediate and sustained humanitarian access in the Deraa and Damascus areas of war-torn Syria, where more than 20,000 Palestinian refugees live.
In an interview with Al Jazeera, Chris Gunness, spokesperson for the UN agency for Palestinian refugees (UNRWA), said an estimated 17,500 Palestinians remained "inaccessible" in the Deraa province, along with another 5,000 civilians in Khan Eshieh.
"UNRWA is extremely concerned about the safety and liberty of every Palestine refugee and each of its staff," Gunness said.
Last week, UNRWA was able to deliver aid to neighbouring areas of Yarmouk, the besieged Damascus-area camp home to both Palestinians and Syrians, for the first time in nine months.
Yet the agency has been unable to gain access to Yarmouk's interior since late March 2015, days before the Islamic State of Iraq and the Levant (ISIL) invaded and took control of most of the camp.
Between 5,000 and 8,000 Palestinian refugees live in Yarmouk today, according to the Jafra Foundation.
Already vulnerable as refugees, many Palestinians in Syria were displaced yet again during the five-year conflict, including 42,500 to Lebanon, 15,500 to Jordan and another 6,000 to Egypt, according to the UK-based Action Group for Palestinians of Syria.
The Action Group has documented the deaths of at least 3,154 Palestinians throughout the war. Another 1,059 are believed to be behind bars in the government's jails, while 282 are missing.
While some have joined armed groups loyal to President Bashar al-Assad, and others have thrown their lot in with rebel groups, most Palestinian refugees are caught in the civil war's crossfire.
Elsewhere, UNRWA has been unable to reach camps in the Deraa area, as well as the Khan Eshieh camp in southern Damascus, for more than two years.
Al Jazeera spoke to Gunness about recent developments in Palestinian refugee camps across Syria.
Al Jazeera: More than 20,000 Palestinian refugees in Deraa and Khan Eshieh have been exposed to "armed conflict, violence and humanitarian deprivation", according to UNRWA. Can you elaborate on the situation for Palestinian camps other than Yarmouk?
Chris Gunness: UNRWA has been able to maintain basic healthcare in Khan Eshieh, thanks to the work of staff living in the camp and running the UNRWA clinic inside the camp.
Limited traffic in and out has been permitted for civilians, enabling them to receive medicines which are unavailable in the camp at a nearby UNRWA health facility.
Similarly, civilians have been able to receive cash and food assistance at distribution points near the camps.
A large proportion of the population of Deraa camp was displaced or fled, leaving the camp largely uninhabited. There has been no UNRWA access to Deraa camp since late 2012,when the camp was regularly struck by explosive munitions, causing widespread damage, including to several UNRWA schools and health clinics.
No UNRWA facilities are currently operational in the camp. There is still very limited civilian traffic in and out of the camp, to access services and assistance in Deraa City, albeit via a highly dangerous route.
School attendance and learning opportunities are regularly interrupted by armed conflict. In all areas, children have been exposed to horrific levels of armed violence, prolonged displacement and severe hardships.
The villages of Mzeirib and Jillin, west of Deraa city, are under the control of opposition armed groups.
Resident UNRWA staff continue to provide education and health services, but no humanitarian missions or deliveries have been possible on account of the ongoing armed conflict in the area. Palestine refugees must travel to Deraa city to receive assistance and some services.
UNRWA remains extremely concerned that civilians from these areas continue to endure deprivations and deplorable living conditions, including sustained exposure to armed violence, as the areas continue to be affected by the conflict.
Al Jazeera: At least 13 Palestinian children were killed near a government-run school by the bombings in Sayyida Zainab on February 21. How emblematic is this of the plight of Palestinian children throughout the conflict?
Gunness: School attendance and learning opportunities are regularly interrupted by armed conflict. In all areas, children have been exposed to horrific levels of armed violence, prolonged displacement and severe hardships.
In Khan Eshieh, children have been able sporadically to attend a school facility near to the camp. In Mzeirib and Jillin, UNRWA has provided children with self-learning materials to enable them to continue informally to study.
Al Jazeera: How have Palestinian camps been affected by armed activity throughout the ongoing fighting in Syria?
Gunness: In the course of the war in Syria, several Palestine refugee camps in Syria have been engulfed by the armed conflict, as armed groups have approached or entered the camps, triggering armed responses from government forces.
The affected camps include Ein al-Tal in northern Syria, Yarmouk, Khan Eshieh, Khan Dannoun in rural Damascus, and Deraa camp, Muzeirib and Jilin in southern Syria.
READ MORE: ISIL takeover of Palestinian camp in Syria a 'siege within a siege'
All sides have deployed in and around Palestine refugee camps heavy weapons with indiscriminate effect.
Al Jazeera: Beyond humanitarian aid, what is the most pressing need for Palestinian refugees in Syria?
Gunness: As for Syrians, the most pressing need for Palestine refugees is for an end to the Syria war; a long-term, durable cessation of hostilities that enables them to recover a semblance of the safe refuge that Syria had provided to them since 1948.
With time and substantial international support, such a cessation will eliminate the grave threats to lives, wellbeing and livelihoods that plague Syrians and Palestinians alike.
It could also generate opportunities for economic recovery, which in turn could enable Palestine refugees to find work and help them to emerge from entrenched, chronic poverty.
Before the crisis, a significantly higher proportion of Palestine refugees fell below the poverty line than the Syrian population: 11.7 percent of Syrians were living below the national poverty line of approximately $1.50 per day, whereas 27 percent of Palestine refugees fell below an even lower poverty line of $1 per day.
As Palestine refugees remain trapped in an increasingly complex and deadly conflict, it is important that their plight is not forgotten.
Follow Patrick Strickland on Twitter: @P_Strickland_
Source: Al Jazeera