Paris ? The French premier on Tuesday announced tightened controls on immigration, part of his government’s response to the country’s worst civil unrest in four decades.

Authorities will increase enforcement of requirements that immigrants seeking 10-year residency permits or French citizenship master the French language and integrate into society, Dominique de Villepin said.

France also plans to crack down on fraudulent marriages that some immigrants use to acquire residency rights and launch a stricter screening process for foreign students, Villepin said.

Anti-racism groups widely opposed the measures, saying that greater government scrutiny of immigrants could stir up racism and racist acts.

Both Villepin and Interior Minister Nicolas Sarkozy have announced law-and-order measures since the rioting broke out this month in depressed suburbs where many immigrants live. The two – both members of President Jacques Chirac’s conservative party – are expected to run for president in 2007, and both want to appear firm in response to the violence and France’s broader social problems.