Protests against a new youth labor law heated up in France on Friday as police detained some 300 people nationwide, the French Interior Ministry said.

The ministry said some 257,000 people took part in the protests in 80 towns and cities across France, while organizers said the figure was as high as half a million.

In the capital only, 187 people had been arrested, Paris police chief Pierre Mutz said on Friday, adding that in clashes with protesters, 46 police officers were injured and 11 of them hospitalized.

According to Mutz, 2,500 police were deployed in Paris on Thursday when the protests heated up overnight in the Latin university district. Several shops' show windows were broken, and five rioters who had broken windows of jewelry shops were arrested.

"We can't put one policeman in front of every shop," Mutz said.

Interior Minister Nicolas Sarkozy blamed militants, "hooligans" and "louts" from suburbs of Paris for the violence.

"There were a few hundred delinquents who came to fight," he told journalists after meeting police and firemen in central Paris.

"Among them there were extreme left and extreme right hooligans and louts from a number of neighbourhoods."

Demonstrations were also held in big French cities including Marseille, Lyon and Grenoble in the south and southeast, in Bordeaux in the southwest, Rennes and Lille in the northwest and north, Clermont-Ferrand, in Limoges and Angers in the center and Strasbourg in the east.

Police used tear gas in clashes with youths in the cities, leaving several injured.

Trade unions have called for a further day of protest on Saturday. The head of the CGT union, Bernard Thibault, has vowed to "step up a gear" in the standoff with the government.

Two-thirds of France's 84 universities were hit by protests with 21 closed and 37 others badly disrupted, the Education Ministry said, adding that protests were also reported in dozens of high schools.

Demonstrators demanded that the government scrap the First Employment Contract (CPE), which allows employers to fire without explanation newly hired workers under the age of 26 within two years.

They said the law infringes workers' rights, making it harder for young people to get long-term employment.

French Prime Minister Dominique de Villepin said through a nationwide televised broadcast on Sunday that the law would come into effect as planned, but he promised new "guarantees" over training and severance pay.

France has one of Europe's highest youth unemployment rates, with 23 percent of the country's young adults out of work and about 40 percent in some of the poor high-immigration city suburbs jobless.

Source: Xinhua