UNHCR report says more than half of those displaced are children, with aid organisations reaching breaking point

The number of people forced to flee their homes across the world has exceeded 50 million for the first time since the second world war, an exponential rise that is stretching host countries and aid organisations to breaking point, according to figures released on Friday.

Half the world's refugees are children, many travelling alone or in groups in a desperate quest for sanctuary, and often falling into the clutches of people traffickers, the annual UN high commissioner for refugees (UNHCR) global trends report said.

More than 25,000 unaccompanied children lodged asylum applications in 77 countries last year, a fraction of the number of displaced minors across the globe.

"We are witnessing a quantum leap in forced displacement in the world," António Guterres, head of the UN's refugee agency, said as figures for 2013 showed a total of 51.2 million refugees, asylum seekers and internally displaced people. If displaced people had their own country it would be the 24th most populous in the world.

Source: UNHCR

The increase of 6 million over the 2012 figures has mainly been driven by the war in Syria. By the end of last year, 2.5 million Syrians had fled across the country's borders and 6.5 million were internally displaced – more than 40% of the population.

Conflicts in the Central African Republic and South Sudan also contributed to rising numbers.

The data represented "a world where peace is dangerously in deficit", said Guterres. "And that peace deficit represents the incapacity of the international community firstly to prevent conflicts and secondly, to find solutions to those conflicts."

Some conflicts were unpredictable, but in other cases "there are situations you see coming, but nothing is done to avoid the conflict". He cited the "enormous risks" in Nigeria as an example, adding that "the international community has shown very little capacity to do something useful to prevent it from getting worse and more dangerous".

Humanitarian organisations could only mitigate the impact of conflict on ordinary people. "There is no humanitarian solution … The solution is political and the solution is to solve the conflicts that generate these dramatic levels of displacement."

Factors that forced people to leave their homes included climate change, population growth, urbanisation, food insecurity and water scarcity – many of which interacted with and enhanced each other.

"It's sometimes difficult to identify the main motivation," said Guterres, adding that movement could be due to several factors.

"The classic idea that you have economic migrants who want a better life, and refugees who flee conflict and persecution – it is true, but now you have a number of people who are forced to move by a combination of reasons, which are not always obvious."

The number of forcibly displaced people in 2013 exceeded the populations of countries such as South Africa, Spain or South Korea, the UNHCR reported. An average of 32,200 individuals were forced to flee their homes each day.

It defined three groups:

• Refugees – 16.7 million people worldwide. Apart from 5 million Palestinians, the biggest refugee populations by source country are Afghans, Syrians and Somalis, which together account for half the total. The main host countries were Pakistan, Iran, Lebanon, Jordan and Turkey. Eighty-six per cent of the world's refugees are hosted by developing countries – up from 70% a decade ago.

• Asylum seekers – close to 1.2 million people submitted asylum claims, mostly in developed countries. In terms of country of origin, the highest number was from Syria (64,300), followed by the Democratic Republic of Congo (60,400) and Burma (57,400). Germany was the largest recipient.

• Internally displaced people – a record 33.3 million were forced to flee their homes but remained within their country's borders.

Many of those crossing borders fell into the hands of increasingly sophisticated people-trafficking gangs, said Guterres. "We see these networks of trafficking and smuggling becoming more and more international, multinational, and linked to other forms of international criminality", such as guns and drugs.

"They become very powerful organisations. And the truth is that national authorities, especially in the developing world … have a very limited capacity to crack down on them."

At the same time, he added, "their behaviour has become more and more vicious". Gangs used rape, torture, sexual exploitation, organ harvesting, extortion and murder. "We are very strongly in favour of international cooperation to crack down on these gangsters,: he said.

The scale of the refugee crisis was straining the capacity of humanitarian organisations, said Guterres. UNHCR has halved the proportion of its budget spent on headquarters costs, but there was an increasing gap between needs and resources available.

"Because conflicts are multiplying, because of climate change and other factors, we see the needs are increasing exponentially."

The UN's world food programme had been forced to reduce rations in some refugee camps because of reduced budgets and greater demands, he said. "Humanitarian organisations are under tremendous stress."