French President Nicolas Sarkozy said Friday that anyone of foreign origin attacking the police would be deported and deprived of French nationality.

"French nationality should be taken away from anybody who has threatened the life of a police officer or anybody involved in disturbing public order," Sarkozy said during his visit to Grenoble, in eastern France, where there were riots and violence earlier this month after a suspected robber was shot dead by police.

The French police claimed that 27-year-old Karim Boudouda was involved in an armed hold-up, and killed him during the chase.

The French president said this was only one of a series of measures adopted by the government to curb violence following two recent incidents in France.

Other measures, he said, include raising the minimum sentence for all serious crimes like attacks on public officials, 30-year prison terms for killing a policeman, and the wearing of electronic tags for repeat offenders upon release.

Sarkozy said that the government would also review welfare payments to non-documented immigrants living in France, and proposed that a juvenile delinquent of foreign origin would lose the privilege of an automatic French citizenship upon turning 18 years of age.

Under French law, any child born to immigrants in France can automatically obtain French citizenship on condition that the child has lived in France for at least one year and remains in the country upon turning 18.

Many immigrants from North Africa and sub-Saharan Africa have engaged in riots, burning cars and shops after Boudouda's death. They even threatened to kill police officials and opened fire when confronted by them.

Just two days after the Grenoble unrest, a similar disturbance occurred in Saint-Aignan, in central France, making the situation spin out of control.

Opposition parties, however, are wary of Sarkozy's "national war on crimes."

Left-wing Socialist Party spokesman Benoit Hamon criticized Sarkozy's statement as "a worn-out speech." He suggested Sarkozy should do his homework and investigate why violence was on the rise in France.

Centrist Democratic Movement Party leader Francois Bayrou called Sarkozy's speech "a big show." This wouldn't help solve France's problem of crime, he said.

French police have started to disband the illegal camps of Roma immigrants this week after Interior Minister Brice Hortefeux reiterated Sarkozy's blame on minorities by vowing to disband illegal Gypsy camps and expel immigrant Gypsy offenders.

A poll last week showed Sarkozy's popularity rating to be as low as 35 percent, the lowest since he took office in 2007. Another survey by the pollster Ifop showed that nearly 60 percent of the French believe social security is deteriorating while criminality is rising