ATHENS, Greece (AP) — The Latest on the flow of migrants into Europe (all times local):

12:25 a.m.

The first Syrians sent from Turkey as part of a deal with the European Union meant to curb illegal migration have landed in Germany.

The 16 Syrian refugees landed in the central German city of Hannover Monday morning aboard a scheduled flight from Turkey and were being taken to accommodation in the region, news agency dpa reported. Another 16 Syrians were expected in Hannover later in the day.

Last month's EU-Turkey deal aims to control the mass influx of people into Europe, many of whom have crossed the Aegean Sea with the help of smugglers. Returns to Turkey of migrants arriving illegally in Greece who didn't apply for asylum or had their claims rejected started Monday; in return, EU countries are to take in Syrians with legitimate asylum claims.

12:20 p.m.

The Hungarian army says it is reinforcing parts the fence built on the southern border with Serbia meant to stop migrants from entering.

The army says it is complying with a request by the interior ministry due to the increased number of migrants being caught near the border.

Hungary built fences protected by razor wire along its borders with Serbia and Croatia last year, drastically reducing migrant arrivals from up to several thousand a day to a few dozen or less but more and more have come since January.

Police data showed that 553 migrants were detained in January, the figure rose to 2,398 in February and 3,401 in March. Last year, over 390,000 migrants entered the country, nearly all passing through on their way to Germany and other richer destinations in Western Europe.

9:50 a.m.

The first vessel transporting migrants from Greece has docked in Turkey, putting into practice a European Union plan to stem migration to Europe.

At dawn on the Greek island of Lesbos, an initial group of migrants were escorted onto two small ferries by officers from the EU border protection agency, Frontex.

The first vessel, the Nazli Jale, reached the port of Dikili accompanied by the Turkish coast guard.

Turkey's state-run Anadolu Agency put the number of migrants at 131 and said they were mostly Pakistani nationals. A Turkish government official told the AP authorities were expecting 202 people. The official spoke on condition of anonymity because he was not authorized to speak publicly on the issue.

A total of 50,000 migrants and refugees are stranded in Greece following EU and Balkan border closures, but only those who arrived after March 20 will be detained for deportation.

—by Dominique Soguel

Police on the Greek island of Lesbos have begun placing migrants and refugees on boats bound to Turkey, the first to be deported under a European Union plan to limit the amount of migration to Europe.

Under heavy security, the first 135 migrants were being escorted onto the boats as dawn broke Monday by officers from the EU border protection agency, Frontex, to nearby ports on the Turkish coast, under the plan which has been strongly criticized by human rights groups.

About 4,000 migrants and refugees have been detained on Greek islands since the agreement came into effect March 20.

On the nearby island of Chios, riot police clashed with local residents hours earlier during a protest against deportations planned there.