Amsterdam  - Four men who the Netherlands want extradited from Belgium have been monitored for years by the Dutch intelligence service AIVD on suspicion of terrorist activities, the country's daily newspaper Volkskrant wrote Friday.

Kenya arrested the four on Monday close to the border with Somalia. They were allegedly on their way to a jihadist training camp in Somalia.

The four men who are now in Belgian custody arrived in Brussels on Thursday following their deportation from Kenya the previous night.

The Netherlands said it would seek the four men's extradition from Belgium.

The three Dutch-Moroccan nationals and one Moroccan with permanent Dutch residency were part of a 20-member multi-ethnic group located in The Hague.

Family, friends and Muslim clerics informed the AIVD several times about the alleged jihadist views of the group, whose members are between 17 and 28 years old.

Even the As Soenna mosque - which itself is closely monitored by the AIVD for alleged extremist views - warned the Dutch authorities about the group's radicalization, Volkskrant wrote.

Last year, imam Fawaz Jneid of the As Soenna mosque formally distanced himself from Al Qaeda.

As a result, the group allegedly felt estranged. Family and friends feared that without a spiritual leader, the young adults would decide to embark on a jihad, or Muslim holy war.

In November 2008, Dutch police arrested one Turkish group member for illegally possessing arms. He was later sentenced to four months imprisonment. (dpa)