During the 1990s, the Netherlands opened its borders for Muslim refugees from countries like Bosnia and Herzegovina, Somalia, Iraq, Iran and Afghanistan. Of the immigrant ethnic groups, 100% of Bosniaks; 99% of Moroccans; 90% of Turks; 69% of Asians; 64% of other Africans, and 12% of Surinamese were Muslims. Muslims form a diverse group. Social tensions between native Dutch and migrant Muslims began to rise in the early 21st century, with the murder of politician Pim Fortuyn by militant animal rights activist Volkert van der Graaf and the murder of Theo van Gogh by extremist Muslim Mohammed Bouyeri, part of the Hofstad Network.