Lady Gaga has cancelled her Paris concerts as nationwide protests continue in France in a standoff over a bill to raise the retirement age.

The French Senate is wrapping up debate on the pension reform bill and could vote on it today.

Students are planning nationwide protests to urge legislators to strike it down.

More than a quarter of the nation's petrol stations were out of fuel because strikers have been blocking oil refineries and fuel depots.

Lady Gaga's website says the singer postponed two Paris concerts "as there is no certainty the trucks can make it" to the show.

In Marseille today passengers carried luggage on foot to reach the airport, blocked by union protesters.

The Marseille airport blockade was lifted after police came in and dispersed the protesters.

Wildcat protests blocked train lines around Paris and protesters in cars and trucks blocked several roads around the country, from near Calais in the north to the Pyrenees in the south.

Interior Minister Brice Hortefeux lashed out at "certain people who take pieces of our territory for battlefields." He said 1,901 people have been detained since early last week.

Hortefeux insisted that the country has several weeks of petrol reserves and that "the trend is toward improvement" in supplies. Still, he said a quarter of France's petrol stations lack fuel.

Students shut down the Turgot High School near the Place de la Republique in eastern Paris after a student union vote. Teens sat in the middle of the street, barring vehicle traffic. Some sang songs and chanted labour slogans while police guarded the area.

Finance Minister Christine Lagarde said both the strikes and the violence were taking an economic toll.

New violence broke out in Lyon today, where police chased rampaging youths who overturned a car, and tried to subdue the violence with tear gas.

President Nicolas Sarkozy stuck firm to the pension reform today insisting it's "an affair of national interest."