An Iraqi Kurdish man has been arrested at Athens airport in possession of a passport known to have been among a haul of official documents stolen by Islamic State jihadists in Iraq, Greek police said Monday.

The 37-year-old, who lives in Athens, was detained after flying in from the Turkish city of Istanbul on Sunday, police said in a statement.

The passport was one of a batch of blank travel documents seized by IS fighters during a raid in Nineveh province, and subsequently cancelled by Iraqi authorities, the statement added. Police did not say when the raid took place.

Greek police routinely uncover false or illegal travel documents among migrants hoping to reach northern or western Europe.

Security concerns in Europe are high after revelations that some of the jihadists behind the Paris terror attacks in November slipped into Europe by posing as refugees.

On Sunday, Greek police said they had arrested two men with Swedish passports suspected of links to jihadist groups.

The suspects -- a 28-year-old man of Bosnian descent and a 19-year-old of Yemeni origin -- were carrying machetes, army uniforms and other combat paraphernalia and will be taken before a magistrate on Tuesday.

The 28-year-old is known to European authorities for ties to jihadists, having been convicted in the past for planning a terrorist attack and was under surveillance by Swedish authorities, police sources said.

A European Union report compiled in November said Greece was failing to properly register and fingerprint migrants, but Athens insists the situation has drastically improved with the arrival of additional EU staff and registering equipment.

Greek leftist Prime Minister Alexis Tsipras on Monday said accusations of negligence based on a two-month report were "unfair".

"Now is the time to prove that Greece is meeting its obligations... we have decided to speed up procedures," Tsipras told visiting European Migration Commissioner Dimitris Avramopoulos, who is also Greek.

The government on Sunday decided to send the army to complete registration centres -- known as hotspots -- on five Aegean Sea islands handling the bulk of refugee and migrant arrivals from neighbouring Turkey.

Tsipras has pledged to have the five centres fully operational later this month.

Two army camps near Athens and Thessaloniki will also be allocated to house up to 8,000 refugees awaiting relocation to other European countries, the government said.