A Greek policeman has been suspended for allegedly wielding a knife and slapping a migrant who had arrived on the island of Kos.

The Hellenic Police Headquarters ordered an urgent inquiry into photographs posted on social media on Monday that portrayed "reprehensible actions of a police officer", a statement on its website said.

The policeman holding a knife allegedly roughly pushed back migrants crowding outside a local authority building, slapping one man across the face as he shoved others, telling them to get back behind a line he drew on the pavement with the knife.

The scene was filmed by an Associated Press cameraman, before another policeman put his hand in front of the camera and made him stop filming.

A migrant jumps over a fence as hundreds wait for a registration procedure outside a police station in Kos [AP]

More than 150 migrants in at least six boats had arrived on the shores of the island that day.

They were among 1,417 migrants rescued by Greece's coast guard from several of its islands over the past three days, authorities said on Monday.

Those figures do not include the hundreds of others who manage to reach the islands' coasts themselves, walking to the main towns to turn themselves in to local authorities and receive registration papers.

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Most migrants land on the five islands of Lesbos, Chios, Kos, Samos and Leros.

The new arrivals add to the 124,000 migrants who have reached Greece by boat in the first seven months of 2015 alone, a staggering 750 percent increase from the same period last year, according to the United Nations' refugee agency.

In July alone, there were 50,000 arrivals, about 70 percent of whom were from Syria.

Tens of thousands of people, many of them fleeing conflict in Syria and Afghanistan, have been making their way from the Turkish coast to nearby Greek islands in inflatable dinghies, overwhelming cash-strapped and understaffed authorities on the islands.

The majority then head to mainland Greece and from there, try to reach more prosperous European countries by either walking across the Balkans from northern Greece, or sneaking onto Italy-bound ferries from the west.

The 1,417 migrants rescued between Friday and Monday were picked up at sea in 59 incidents off the coasts of the islands of Lesbos, Chios, Samos, Agathonisi and Kos, the coast guard said.

Source: Al Jazeera and agencies