The number of refugees who have fled the war in Syria now exceeds five million with millions more displaced internally, according to the UN.

Syrians have poured across their borders since anti-government protests in 2011 spiralled into a full-blown conflict between rebels, government troops, and foreign backers.

The first three months of 2017 saw more than 250,000 additional Syrians register as refugees bringing the total to 5.1 million, the UN's refugee agency UNHCR said on its website, without providing an explanation for the apparent surge.

"It's not about the number, it's about the people," said UNHCR spokesman Babar Baloch, noting the conflict had now lasted longer than World War II. "We're trying to look for understanding, solidarity and humanity."

Turkey continues to host the highest number of Syrians displaced by the conflict - nearly three million people. It saw an increase of 47,000 more refugees since February, Baloch said.

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The five-million milestone came a year to the day after UNHCR asked other countries to start resettling at least 10 percent of the most vulnerable Syrian refugees. So far only 250,000 places have been offered.

"We're asking for more legal pathways for Syrians to travel to other countries so that they don't end up dying in the seas like in the Mediterranean," said Baloch.

Al Jazeera's Andrew Simmons, reporting from Geneva, said the "enormity and colossal suffering" of the refugees is evident from the UNHCR report.

The total number of Syrian refugees abroad stood at 4.6 million at the end of 2015 and rose to 4.85 million by the end of last year, according to the agency's data.

The agency estimated another 6.3 million people have been internally displaced.

Financial aid falling short

Lebanon has more than one million Syrian refugees, while Jordan has 657,000, with others spread across Iraq, Egypt and other North African countries.

Al Jazeera's Alan Fisher, reporting from Lebanon's Bekaa Valley, said the actual number of Syrian refugees in Lebanon is much higher than the official figure, with more people streaming into the country in the last few weeks.

He said most of the new arrivals have not yet registered with the UN, and shortages of food and water is common.

War-torn Iraq also hosts 233,224 Syrian refugees in the Kurdish north.

Iraq itself has an estimated 3.5 million people internally displaced, according to Al Jazeera's Hoda Abdel Hamid, reporting from east of Mosul.

Hundreds of thousands of Syrians have also fled to Europe, but not all have been granted refugee status.

Syrians have also fled to Europe in large numbers, making 884,461 asylum claims between April 2011 and October 2016. Almost two-thirds of the claims were in Germany and Sweden.

Hundreds of thousands more live in Gulf countries that are not party to the 1951 Refugee Convention, such as Saudi Arabia, Qatar, and the United Arab Emirates, so they are not recorded as refugees.

A UN-led humanitarian appeal to help Syrian refugees and support host communities has received only six percent of the money needed this year - $298mn out of $4.6bn target.