ATHENS - A four-year-old boy died on a boat crossing the Aegean Sea, the Greek coastguard said Wednesday, as the flow of refugees and migrants increased again after a brief drop in numbers.

The body of the boy, identified as Afghan by aid groups, was found in a boat that landed on the island of Chios, the coastguard said. His family were among 600 migrants who arrived on the island on Wednesday, the day after the government inaugurated a registration facility to regulate the influx to Greece's eastern Aegean islands after over 800,000 people fleeing war and poverty landed there last year.

Similar facilities, known as hotspots, will operate on the islands of Lesbos, Leros, Samos and Kos at the insistence of the European Union, which wants to keep additional economic migrants out of the continent, and prevent possible extremists from sneaking in under the guise of refugees. Lesbos gas seen another 1,076 people arrive since Tuesday, after Greek authorities said the flow had dropped from around 2,500 arrivals per day to 200.

"There has been a slight pick-up in arrivals," a coastguard source said. Turkey is hosting 2.5 million refugees from Syria's civil war and hundreds of thousands from Iraq, and is increasingly bitter that it has been left to shoulder the burden. A summit will be held in Brussels on Thursday between Turkey and eleven EU members to debate a German idea of flying refugees directly to Europe, and thereby reducing the number of deaths in the Aegean. Over 300 people have already died in the crossing this year according to the International Organisation for Migration.

Moreover, Austria's interior minister said Wednesday the country would cap the daily number of asylum claims at 80 to slow down the migrant flow at its southern borders.

In addition, the government will grant entry to a total of 3,200 migrants per day "who want to seek asylum in a neighbouring state", Johanna Mikl-Leitner told the APA news agency.

"Austria is among the EU countries most under strain and is reaching breaking point. It stands to reason to want to secure your own borders when there is no European solution," she said. The measure will enter into effect on Friday, the minister added. The move comes a day after Vienna said it would step up controls at existing checkpoints along its southern frontier with Italy, Slovenia and Hungary to curb the influx of migrants and refugees trekking up along the Balkans.

The daily limit on asylum claims is in line with Austria's announcement last month that it would only take in 37,500 asylum-seekers this year -- sharply down from the 90,000 it accepted in 2015. Since January, the country of nearly nine million has already received 11,000 asylum claims, or around 250 a day. The government has not yet specified what it plans to do once the annual quota is reached.

In reaction to Austria's restrictions, Slovenia and Croatia have also toughened controls -- a "domino effect" welcomed by Mikl-Leitner. "It is important that every country along the Balkan route tightens its borders," said the minister who sees the building of a "fortress Europe" as a solution to Europe's worst migration crisis since World War II. In 2015, over one million people reached Europe's shores -- nearly half of them Syrians fleeing a civil war that has claimed more than 260,000 lives.

The vast majority enter the EU through Italy and Greece, where they should register, but poor controls mean most are able to continue their journeys to northern Europe. Earlier Wednesday, Austrian Chancellor Werner Faymann was quoted as saying he expected Germany to follow his tougher migrant stance and clamp down on the number of asylum-seekers allowed into the country. Faymann said Austria still supported a deal proposed by Germany, under which Turkey would seal its borders and then fly refugees to Europe where they would be settled under an EU quota system.

But in the face of the plan's sluggish implementation, Vienna has also joined the so-called "Visegrad Four" -- Hungary, Poland, Slovakia and the Czech Republic -- in wanting tighter border controls inside the EU's passport-free Schengen zone. On Thursday, Faymann and his German counterpart Angela Merkel will host talks with nine EU countries and Turkey in Brussels, before a summit the same day involving all 28 bloc leaders.