A week into the violence across Israel-Palestine in May, which began with protests against forced displacement of Palestinians in Jerusalem's Sheikh Jarrah district and culminated in a bombing campaign on Gaza that killed hundreds of people, mostly Palestinians, groups of pro-Palestine demonstrators gathered at the Lebanese border to the north and the Jordanian border to the east.

"The border must be opened so that we can defend al-Aqsa and Jerusalem to the death," 23-year-old Mohammed Khalil, a protester in Amman, told AFP, referring to al-Aqsa Mosque compound, one of Islam's holiest sites, in East Jerusalem.

According to the Middle East Eye (MEE), Many of the more than five million Palestinian refugees living in diaspora communities after they - or their ancestors - were forced out of their homes feel an umbilical connection with events in Palestine, born out of a determination to return and redress a sense of deep historical injustice.

In 1947-48, during what was known as the Nakba, or Catastrophe, roughly 800,000 Palestinians were forcibly displaced when the United Nations partitioned Mandatory Palestine and Jewish paramilitary groups destroyed and depopulated Palestinian areas. An estimated 15,000 Palestinians were killed, and 418 towns and villages were ethnically cleansed and eradicated.

Then, after the 1967 Six Day War, known by Palestinians as the Naksa, at least 300,000 more people (including some Syrians) were kicked out of their homes or fled when Israel seized and occupied territories including the Golan Heights, the West Bank, with it East Jerusalem, and the Gaza Strip. Many of the newly displaced people had earlier been forced from their homes in 1948.

Today, 74 percent of the Palestinian population are refugees.

Many live in decades-old camps in the West Bank, the Gaza Strip, Jordan, Lebanon and Syria, some of which are administered by the United Nations Relief and Works Agency for Palestinians in the Near East (UNRWA).

Palestinian refugees often have fewer rights than locals. The longing for home back in Palestine is often aggravated by a sense that they are not welcome where they have settled.

Solidarity protests, noisy with clapping and chants, have often started at the entrances of Palestinian refugee camps in Lebanon, Jordan, and Syria among other areas.

At the centre of al-Baqa'a refugee camp, just north of the Jordanian capital, Amman, and Jordan's biggest camp for Palestinians, stands a large statue of a key. Many of those displaced in 1948 and 1967 brought with them, and still have, the keys to their homes back across the Jordan valley.

Estimates vary, but roughly half of Jordan's 10 million-strong population is of Palestinian descent.

There are also more than 2.1 million Palestinian refugees registered in Jordan. Most have full citizenship rights, but the 140,000 refugees who went first to Gaza in 1948 and then to Jordan in 1967 - known as "children of Gaza" - do not have legal status. They are denied even basic services, including schooling and healthcare.

"Like any other Palestinian inside [Israel-Palestine] we are affected by what is happening. We are proud of the honourable position of the resistance, and we wish we could be with them. We believe that today or tomorrow or even the last day in our lives we will return to our homeland", a refugee woman told MEE.

"We have seen the recent events in Palestine and are very sad about what is happening there," Suzan Ahmed, a 42-year-old refugee who was born and raised in Syria's Hama, about 200km north of Damascus, also told MEE. "This is our land from which we were forcibly displaced. We hope that our suffering will end here... and we will return to our country and visit al-Aqsa."

Over half-a-million Palestinian refugees lived in Syria before war erupted in the country in 2011. According to UNRWA, some 120,000 of these refugees have fled Syria since the beginning of the conflict, while 60 percent of Palestinians in Syria have been displaced at least once in the past decade. Some 1,500 Palestinian families are estimated to have fled to Idlib, a further 100km north of Hama and the last rebel-held province in the country.

Populated refugee camps, most prominently Yarmouk, were brutally besieged by the forces of President Bashar al-Assad during the war, their residents reduced to eating grass and leaves to survive.