COPENHAGEN (Reuters) - Militant Islamist groups are not believed to be using the refugee influx into Europe to smuggle in militants who could carry out attacks, the head of Denmark’s country’s intelligence service (PET) said on Tuesday.

Among the almost half a million people who have fled from war and poverty to Europe this year, some 12,400 have entered Denmark this month. This has stirred concern, especially from anti-immigration Danish People’s Party, that radical Islamists may be posing as refugees to enter Europe and launch attacks.

“Based on our intelligence, we believe organised Islamic militants would not use people-smuggling networks or refugee routes to try to get terrorists into the West, including to Denmark,” PET chief Finn Borch Andersen told a news conference.

The routes involve too many safety hazards and also a great risk of being discovered by police or other refugees, many of whom fled militant Islamists themselves, Andersen said.

Some radical Islamist groups have said they intend to use the refugee wave to get into Europe, but that is a “deliberate deception”, Andersen said, although he could not wholly rule out that a few people sympathetic to militant Islam could come.

Security officials in Germany, which has taken in the largest number of refugees, have also said they have found no proof that jihadist militants are among them.

Right-wing, anti-immigrant parties in some other European Union states have voiced concerns about possible militant “infiltration” similar to that of the Danish People’s Party.

Andersen said PET assessed militant threats to Denmark as “serious” but this has not changed for several years.

The influx of refugees and migrants, two-fifths of them from Syria, has overwhelmed the European Union’s southern rim states and plunged the 28-nation bloc into furious disputes over border controls reimposed by some members.

The Danish newspaper Jyllands-Posten sparked a wave of protests across the Muslim world when it published cartoons of the Prophet Mohammed a decade ago.

In February, Copenhagen was shocked by a deadly assault on a free-speech event and a synagogue carried out by a Danish son of Islamic immigrants which then-Prime Minister Helle Thorning-Schmidt described as a “terrorist attack”.

(This refiled version of the story restores dropped word “not” in paragraph five).