More than three times as many migrants were tracked entering the European Union by irregular means last month than a year ago, official data showed on Tuesday, many of them landing on Greek islands after fleeing conflict in Syria.
While the increase recorded by the European Union's border control agency Frontex may be partly due to better monitoring, it highlighted the scale of a crisis that has led to more than 2,000 deaths this year as desperate migrants take to rickety boats.
Italian police said they had arrested eight suspected human traffickers that they said had reportedly forced migrants to stay in the hold of a fishing boat in the Mediterranean as 49 of them suffocated on engine fumes.
Some of those traffickers were accused of kicking the heads of the migrants when they tried to climb out of the hold as the air became unbreathable, prosecutor Michelangelo Patane told a news conference in Catania, Sicily.
The dead migrants were discovered last weekend, packed into a fishing boat also carrying 312 others trying to cross the Mediterranean to Italy from North Africa.
It was the third mass fatality in the Mediterranean this month: last week, up to 50 migrants were unaccounted for when their rubber dinghy sank, a few days after some 200 were presumed dead when their boat capsized off Libya.
Greece appealed to its European Union partners to come up with a comprehensive strategy to deal with what new data showed were 21,000 refugees landed on Greek shores last week alone.
A spokesman for the United Nations refugee agency UNHCR in Geneva said the European Union should help Greece but that Athens, which is struggling with a debt crisis, also needed to show 'much more leadership' on the issue.
Greek officials said they needed better coordination within the European Union. "This problem cannot be solved by imposing stringent legal processes in Greece, and, certainly, not by overturning the boats," said government spokeswoman Olga Gerovassili.
Nor could it be addressed by building fences, she said.
Hungary, which has attracted criticism from the United Nations refugee agency with its plans to build a fence to stem an influx of migrants, said on Tuesday it would send thousands of policemen to patrol the southern border with Serbia.
Hungary reported detecting more than 34,800 people in July crossing its borders from non-EU states, notably via Serbia.
Frontex said it recorded some 107,500 people arriving outside regular channels in July, after a previous record in June of over 70,000, and more than three times as many as July last year.
The most active frontiers were those of the Greek islands in the Aegean off Turkey, where nearly 50,000 people were recorded arriving by sea, mainly on Lesbos, Chios, Samos and Kos.
There were chaotic scenes on the island of Kos last week, where local police locked migrants in an outdoors athletics stadium to process them. On one occasion police sprayed fire extinguishers at the crowds to keep them back.
The Greek state eventually charted a passenger ship to house and process migrants in an attempt to ease conditions onshore, where many are living in tents, some in shelters made from cardboard boxes.
Nearly 340,000 such migrants were seen so far this year arriving in the EU, mainly in Italy, Greece and Hungary. That was a 175 percent rise on the same period last year and much more than the 280,000 registered arrivals in all of 2014.
Other EU data shows 625,920 people claimed asylum in the bloc last year. Frontex officials were not immediately available to comment on how far the increase in numbers being detected may be a result of increased monitoring of the frontiers.
In Germany alone, which recorded 203,000 claims last year, officials said on Tuesday they expect to register some 750,000 refugees this year.
"Syrians and Afghans accounted for a lion’s share of the record number of migrants entering the EU illegally," Frontex said in a statement. "Most of them, fleeing instability in their home countries, initially entered Greece from Turkey."
Frontex Executive Director Fabrice Leggeri said: "This is an emergency situation for Europe that requires all EU member states to step in to support the national authorities who are taking on a massive number of migrants at its borders."