During the same period, Islam increased from essentially nonexistent to 5% of the population. The main sources of Muslim immigrants include Surinam and Indonesia from decolonization, Turkey and Morocco as migrant workers, and Iraq, Iran, Bosnia and Afghanistan as refugees. In the early 21st century, religious tensions between native Dutch people and migrant Muslims was increasing. After the rise of politician Pim Fortuyn, who sought to defend the Dutch liberal culture against what he saw as a "backwards religion", stricter immigration laws were enacted. Religious tensions increased after the murders of Pim Fortuyn in 2002 and Theo van Gogh in 2004, both by conservative Muslims.