A record 41.3 million people were uprooted within their own countries last year due to conflicts and violence, data showed on Friday, with two-thirds displaced in just 10 countries including Syria, Colombia and Somalia.

The increase in internally displaced people (IDPs) - which was 1 million higher than in 2017 - suggested that more global crises were long-lasting, said Alexandra Bilak, director of the Geneva-based Internal Displacement Monitoring Centre (IDMC).

“Unresolved internal displacement has all sorts of knock-on effects - one of them being that IDPs today could become refugees tomorrow,” she told the Thomson Reuters Foundation.

The number of people displaced within their own borders far exceeds those who cross into other countries - with 25.4 million refugees and 3.1 million asylum seekers worldwide in 2017, according to the United Nations refugee agency UNHCR.

Unlike refugees or asylum seekers waiting for decisions on their refugee status, IDPs cannot claim international protection and often have less access to aid and medical care. Ongoing conflict in Syria and the Democratic Republic of Congo, and rising tensions in Ethiopia, Cameroon and Nigeria triggered most of the 10.8 million new displacements in 2018 linked to conflict and violence, the IDMC said.

Internal displacement is a hidden problem in many countries, such as Yemen, where the IDMC estimated 2.3 million people were forced to flee in 2018, although the number could be higher, Bilak said.

“IDPs are certainly the most invisible. There are plenty of countries where we just don’t have an accurate picture of the scale of the phenomenon,” she said in a phone interview.

In addition, disasters - largely extreme weather events such as cyclones and floods - forced 17.2 million from their homes in 2018, mainly in the Philippines, China and India, although such displacement was often short-term, the IDMC said.

Worldwide temperatures are on course to rise by 3 to 5 degrees Celsius (5.4 to 9 degrees Fahrenheit) by 2100, far overshooting a global target of limiting the increase to 2C or less, the UN World Meteorological Organization says.

That is increasing the risk of extreme weather, as well as worsening hunger, poverty and water shortages, scientists say.

The IDMC said it did not produce a cumulative figure for those affected by natural disasters as this is hard to measure because people rapidly move on.

Cities were increasingly bearing the burden of hosting IDPs, both after natural disasters and as a result of urban warfare in places like Syria’s Daraa, Yemen’s Hodeidah and Libya’s Tripoli, the IDMC said.

Bilak said cities needed to find ways to absorb these people.

“Even though the primary responsibility to address internal displacement lies with national governments, there’s a very important role that needs to played by local governments and by municipalities,” she said.

The head of the U.N. Commission of Inquiry on Syria warned Thursday that an all-out conflict in the last major rebel stronghold in Idlib province would very likely increase human rights violations and generate a humanitarian catastrophe.

Paulo Pinheiro told a news conference that the current aerial and ground offensive by the Syrian government and its allies is “a serious escalation” resulting in scores of civilian casualties and the displacement of over 150,000 people in just one week.

The commission, established by the U.N. Human Rights Council, has been gathering evidence of alleged crimes against civilians during the nine-year civil war.

Since the beginning of the year, Pinheiro said, the commission has been investigating deadly attacks against civilians by the Syrian government and its allies in Idlib and northern Hama, including on medical facilities, markets, schools and other civilian infrastructure.

It has also investigated shelling by armed groups, including al-Qaida-linked Hayat Tahrir al-Sham, that has resulted “in scores of deaths and injuries,” he said.

Agencies