BERLIN/washington - Britain and France Monday joined Germany in pledging to accept tens of thousands of refugees as Europe’s record influx of people fleeing war and misery sparked warnings that one Greek migrant chokepoint was “on the verge of explosion”.

European leaders are scrambling for solutions as bloody conflicts in Syria, Iraq and beyond have sent hundreds of thousands of desperate people on dangerous voyages through the Balkans and across the Mediterranean to the 28-nation EU. German Chancellor Angela Merkel, whose country is Europe’s top refugee destination, hailed the warm welcome her citizens gave to 20,000 asylum-seekers who streamed across its southern borders on weekend trains, and pledged billions more in money to house them.

Signalling that the huge wave of arrivals marked a new milestone for Europe’s biggest economy, she said that “what we are experiencing now is something that will ... change our country in coming years”. “We want the change to be positive, and we believe we can accomplish that,” she said. As EU leaders stepped up efforts to tackle the historic crisis, France said it would take 24,000 more asylum-seekers under a European plan to relocate 120,000 refugees from hard-hit frontline countries. And British Prime Minister David Cameron said his country would take in 20,000 Syrian refugees from camps near the war-torn country’s borders over the next five years.

In Greece, the situation on Lesbos island near Turkey was “on the verge of explosion” with the recent arrival of more than 15,000 mainly Syrian refugees, the immigration minister warned. Elsewhere tensions have flared too as about 40 men rioted at a Spanish migrant detention centre in Valencia late Sunday and dozens tried to escape, in clashes that left five police injured. Meanwhile, the poor and desperate kept coming, both on the land corridor through Turkey and the Balkans and on overcrowded boats in the Mediterranean on journeys that have claimed thousands of lives this year.

Underscoring the danger brought home by last week’s shocking image of three-year-old Aylan Kurdi lying drowned in the surf, a Greek passenger ferry on Monday sent its lifeboats to rescue 61 migrants whose boat was at risk of sinking off Lesbos. Libyan coastguards said they had rescued over 120 migrants aboard a rubber boat in trouble on the high seas en route to Europe. Elsewhere migrants rescued by Italian authorities on Sunday said five of their group were still missing..

Moreover, United Nations Secretary-General Ban Ki-moon Sunday appealed to European leaders “to be the voice of those in need of protection” and to quickly find a joint approach to the refugee and migration crisis that shares responsibilities equitably, as Germany and Austria continue to welcome thousands of people fleeing their war-torn homelands.

According to a statement issued by his spokesperson in New York, the Secretary-General spoke by telephone with several European leaders today to discuss the migration crisis. Recognizing the challenges that large-scale refugee and migration flows pose to member states, the UN chief appealed to the leaders to be the voice of those in need of protection and to quickly find a joint approach to share responsibilities equitably.?”

The secretary-general’s call echoes similar appeals from top UN agency officials who have appealed for swift action as the migration crisis in Europe has deepened over the past week. On Saturday, the UN refugee agency, which has appealed to the European Union to admit up to 200,000 asylum-seekers fleeing conflict zones like Syria, Iraq and Afghanistan, welcomed the decision of Austria and Germany to receive thousands of refugees and migrants crossing the border from Hungary over the past 72 hours.

The agency has repeatedly stressed the urgent need to put in place an emergency plan to manage the crisis, and Friday, the UN High Commissioner for Refugees, Antonio Guterres recommended several concrete proposals, saying that dealing with the biggest influx of refugees into Europe for decades requires a “massive common effort” and break with the current fragmented approach, which he said has led Europe overall to fail to find an effective common response.

On Thursday, moved by the “heart-breaking” image of a drowned Syrian refugee boy who washed up on a beach in Turkey that ricocheted around the world on social media, along with equally painful images of children being passed over barbed wire fences by desperate parents, Anthony Lake, Executive Director of the United Nations Children’s Fund (UNICEF) declared: “It is not enough for the world to be shocked by these images. Shock must be matched by action.”

According to Sunday’s statement, Ban in his phone conversations assured European leaders of the UN’s readiness to continue supporting their efforts to develop a response that is effective, feasible and in line with universal human rights and humanitarian standards, including the right to claim asylum. The Secretary-General also commended the leaders for having voiced concern about increasing xenophobia, discrimination, and violence against migrants and refugees in Europe. “He hoped that any manifestation of these phenomena would be addressed firmly and without delay,” the statement added.

As governments have cracked down on ruthless people smugglers charging thousands of dollars for the dangerous sea journeys, Turkey detained a fifth trafficking suspect over two boat sinkings last week, including the one which claimed the life of the three-year-old boy. Germany was meanwhile expecting 10,000 refugees to arrive on Monday, a Bavarian official said, after more than 20,000 arrived on around 100 trains from Hungary through Austria over the weekend.

Merkel hailed as “breathtaking” the emotional and warm welcome given to the thousands of migrants and said Germany was now seen by many abroad as a place of “hope” after citizens turned up in large numbers to shower the new arrivals with gifts, cash and toys. Europe’s top economy — which expects 800,000 asylum requests this year, four times last year’s total — faces extra costs estimated at 10 billion euros ($11 billion) this year and next.

Merkel said that the federal government would contribute six billion euros for new shelters, extra police and language training in 2016. However, despite German solidarity, Merkel stressed that other EU countries must take in more migrants because “only with common European solidarity can we master this effort”.

French President Francois Hollande warned that unless the EU makes a greater collective effort, the core European ideal of open borders will be in peril. “If there is not a united policy, this mechanism will not work, it will collapse, and it will undoubtedly be the end of Schengen, the return of national borders,” he said about the passport-free zone across much of the continent.

But Europe looked far from united as Hungarian Prime Minister Viktor Orban, who has taken a hard line, said quotas would be futile so long as refugees kept streaming in. “As long as we can’t defend Europe’s outer borders, it is not worth talking about how many people we can take in,” Orban said in a speech in Budapest.

Under pressure from Berlin and Paris, the European Union is readying fresh quotas that would see the two top EU economies take nearly half of the 120,000 refugees to be relocated, under a plan by European Commission chief Jean-Claude Juncker.

According to Juncker’s proposal to be unveiled Wednesday, Germany would take over 31,000, France 24,000, and Spain almost 15,000 to relieve the burden on frontline countries Greece, Italy and Hungary, a European source told AFP. Hollande confirmed France would take in 24,000 refugees over the next two years and offered to host an international conference on Europe’s worst refugee crisis since World War II. Meanwhile, Dimitris Avramopoulos, the EU commissioner for migration stressed that “no member state in the European Union can address this issue alone. We can only overcome this crisis if we act as a true union, if we act with responsibility and solidarity.”