More than 31 million people were displaced in their own countries last year — over 75 percent as a result of natural disasters and weather-related events, and the rest from violence and conflicts with Congo and Syria topping the list, according to a new report released Monday.

East Asia and the Pacific accounted for two-thirds of the displacements related to extreme weather events including storms, floods, wildfires and severe winter conditions in 2016 — almost double the number for 2015.

The center, which is part of the Norwegian Refugee Council, said that in recent years there have been roughly twice as many internally displaced people as refugees who flee to another country, and the gap between the numbers has been growing since 1997.

Yet, the report said, "2016 was a year of stark contrast between the attention given to refugees and migrants and the lack of political concern for the millions of people displaced inside their country by conflict, violence and disasters."

The center warned that displacement will continue to have a major impact unless its main causes — poverty, environmental change and state fragility — are addressed. It urged new financial and political investments to tackle the causes of the "displacement crises."

"In 2016, one person every second was forced to flee their home inside their own country," said Jan Egeland, head of the Norwegian Refugee Council. "It is urgent to put internal displacement back on the global agenda."

According to the center, 31.1 million new cases of internal displacement by conflict, violence and disasters were recorded in 2016, an increase of 3.3 million from 2015. The latest figures on the U.N. refugee agency's website showed 14.4 million new refugees in 2014.

A majority of the 24.2 million displacements caused by disasters in 2016 occurred in low- and lower middle-income countries as a result of weather-related events including several severe typhoons and hurricanes, the center said.

The countries with the worst displacement were China with 7.4 million people forced to flee their homes and the Philippines with 5.9 million, India with 2.4 million, Indonesia with 1.2 million and the United States with 1.1 million, the center said.

But it said "small island states suffer disproportionately once population size is taken into account."

Of the 6.9 million new displacements caused by conflict in 2016, the center said sub-Saharan Africa overtook the Middle East as the region with the highest level.

Congo had the highest number of new displacements last year — 922,000 — and overtook Syria, with 824,000, it said. They were followed by Iraq with 659,000 people, Afghanistan with 653,000 and Nigeria with 501,000.

The center said the number of people driven from their homes in Congo was a nearly 50 percent increase from 2015, due to the conflict in the eastern Kivu provinces and an increase in clashes in southern and central regions.

Alexandra Bilak, the center's director, said the upsurge in Congo "highlights how the failure to address the underlying causes of conflict and crisis" result in recurring displacement of hundreds of thousands of people.

According to the report, 12 percent of new displacements in 2016 "were associated with criminal, political or communal violence across the world."

"From gang violence in Central America to post-electoral violence in Burundi, around 850,000 incidents were recorded," it said.

In El Salvador, the center said 220,000 people were displaced by criminal and gang violence last year, "placing the country second in the ranking of highest new displacements relative to population size."