Over five million Syrians have fled the ongoing conflict in their homeland, with ongoing fighting triggering a new exodus of civilians and the world’s largest refugee crisis, the UN Refugee Agency (UNHCR) said on Thursday.

“Countries outside the Middle East must take in more Syrians under long-term resettlement programmes.

“We still have a long road to travel in expanding resettlement,” , UN refugee Chief, Filippo Grandi said.

The tally of Syrian refugees in the Middle East and North Africa had hovered just below five million since the middle of 2016.

Since February, Turkey has registered 47,000 Syrians, most of whom had fled previously, but had not been documented, UNHCR spokesman Babar Baloch told dpa.

Turkey is the largest host country for Syrian refugees, having taken in nearly 3 million during the six-year war.

More than one million Syrians live in Lebanon, while nearly 700,000 have taken refuge in Jordan.

UNHCR called on governments outside the region to resettle 500,000 Syrians one year ago, to alleviate the burden on these countries in Syria’s vicinity.

“Till date, countries have only made available 250,000 places.

“As many states know from first-hand experience, resettlement not only gives refugees the opportunity to rebuild their lives, but also enriches the communities that welcome them,” Grandi said.

The UN high commissioner for refugees also urged countries to create additional legal options that would allow Syrians to enter their countries.

Such legal pathways include family reunification programmes and study visas.

Around 400,000 people are thought to have died in the Syrian civil war, which began in March 2011 with the violent quelling of peaceful protests against the regime of President Bashar al-Assad.

In addition to the people who have fled the country, more than six million have become displaced inside Syria.

The latest wave of displacement took place on Thursday when hundreds of civilians fled areas in north-eastern Syria where U.S.-backed fighters are pushing to drive the Islamic State militants from a key stronghold, a monitoring group reported.

The Syridan Democratic Forces (SDF) a U.S.-backed alliance of Syrian Kurds and Arabs, are attempting to tighten a siege around al-Raqqa that Islamic State’s de facto capital in north-eastern Syria.

The Syrian Observatory for Human Rights said that fighting in the area had prompted hundreds of locals to flee to the SDF-controlled area of Sweidiyeh, north of the strategic Euphrates Dam.

There have been several warnings that fighting had damaged the dam, especially after the Britain-based Observatory reported last week that the facility stopped operation, without specifying a reason.

The Euphrates Dam is the largest in Syria and plays a key role in the country’s electricity generation as well as irrigation of the Euphrates valley, one of the country’s main agricultural areas.

In recent days, SDF forces have captured half of the 4-kilometre-long dam on the Euphrates River from Islamic State.

A local official warned of a “human catastrophe” if the dam is damaged.

He added that some 3 million people live along the banks of the Euphrates River.