ATHENS: Greece said on Tuesday it had set up four out of five proposed registration centers for refugees, drafting in the army to help, after criticism from its European Union peers it was not doing enough to stem Europe's chaotic influx of migrants.

Last week, EU ministers gave Greece three months to fulfill 50 recommendations to fix its borders. If it does not, the EU members of the free-travel Schengen zone can impose checks on internal frontiers for up to two years.

The Greek government drafted in the army last month to ensure the five registration centers and two relocation camps on the mainland were completed on time.

The registration centers are set up on the "hotspot" islands of Samos, Lesbos, Chios, Kos and Leros near the Turkish coast, where migrants leaving Turkey tend to arrive. All but the center on Kos is now ready, and that one will be ready in five days, after opposition from island residents.

Two disused military camps on the mainland will operate as relocation centers, each with a capacity to house up to 4,000 people.

"It was a rather difficult operation," Greek Defense Minister Panos Kammenos, leader of the co-ruling Independent Greeks party, told journalists.

Greece, the main entry point into Europe for more than a million refugees and migrants since last year, has come under fire for failing to control the influx through the sea border it shares with Turkey.

Athens says numbers are too big to handle, that it cannot turn back boatloads of refugees and migrants into the sea, and that Turkey do more to stop the migrants at its shores.

Some residents of Kos protested putting a registration center on the island, saying it would hurt tourism. Scuffles have broken out between protesters and police on the island in recent weeks.