Documentary films, special reports and a memorial tribute to Theo van Gogh are among the activities taking place in the Netherlands on Monday, five years after the filmmaker was slain by a religious extremist.

Van Gogh, who was an outspoken critic of radical Islam and a descendant of the famed painter, is being remembered by politicians, family, friends and fans as the country reflects on how his violent death in Amsterdam in 2004 changed the nation.

"We learned from it," Amsterdam Mayor Job Cohen said in an interview with NOS radio on Monday.

Though the scale of destruction was of course different, Cohen compared the after-effects of the filmmaker's death on the Netherlands to the Sept. 11 attacks on the U.S.

Cohen said his job has been to "just try to hold things together" in diverse Amsterdam, where a host of fire attacks on mosques followed the killing and relations among certain groups still remain tense five years on.

"Every day it's a new challenge all over again."

Backlash from killing

Mohammed Bouyeri, a Dutch-born man of Moroccan descent, received a life sentence for his brutal, public murder of van Gogh. During his trial, he said he attacked the filmmaker because van Gogh had insulted Islam with his newspaper columns and films such as Submission.

After the incident, which grabbed headlines around the globe, the Dutch government responded with stricter measures regarding immigration, including ordering citizenship tests for resident aliens and language tests for prospective immigrants. It also authorized greater powers for the police — including allowing officers to stop and frisk people at random — and made carrying one's ID card at all times a law.

Political watchers also attribute the rise of anti-immigration politicians such as Geert Wilders to van Gogh's death.

Efforts have also been made to stimulate understanding and better relations with immigrant groups and with the country's Islamic leaders. Muslims make up about five per cent of the 16 million people in the Netherlands, with a large number residing in Amsterdam.

"The problem in Dutch society is that there are groups of people who don't trust each other," political scientist Jean Tillie told Agence France-Presse.

With files from The Associated Press