By Adrian Croft and Simon Carraud

PARIS, April 10 (Reuters) - Far-right presidential candidate Marine Le Pen drew protests from her political rivals and the Israeli government on Monday by denying the French state's responsibility for a mass arrest of Jews in Paris during World War Two.

Two weeks before the first round of the election in which she is a frontrunner, Le Pen touched a raw nerve by reopening debate about the state's role in one of the darkest episodes in French history under the Nazi occupation.

"I think France isn't responsible for the Vel d'Hiv," Le Pen said on Sunday, referring to the German-ordered roundup by French police of 13,000 Jews in July 1942.

Most were crammed into the Velodrome d'Hiver cycling stadium, commonly known as the Vel d'Hiv, before being deported to the Auschwitz concentration camp.

"I think that, in general, if there are people responsible, it is those who were in power at the time. It is not France," Le Pen said in an interview with media groups Le Figaro, RTL and LCI.

Le Pen's rivals pounced on her comments, which could set back her attempts to clean up the image of her anti-immigration National Front and distance it from the anti-Semitic views of her father, Jean-Marie Le Pen, the party's founder.

"Some people had forgotten that Marine Le Pen is the daughter of Jean-Marie Le Pen. They haven't changed," centrist presidential candidate Emmanuel Macron told BFM television.

The Israeli foreign ministry said it regretted that anti-Semitism "is raising its head again today".

"This contradicts the historical truth as expressed in statements by French presidents who recognised the country's responsibility for the fate of the French Jews who perished in the Holocaust," a ministry spokesman said.

"Vel d'Hiv" was the top trending topic on Twitter in France on Monday, the first official day of campaigning for the election, whose first round is on April 23.

Gilles Ivaldi, a political scientist at the University of Nice, said Le Pen's remark was damaging for her. "It ... runs completely counter to the party's efforts and gives ammunition to all those who say that the National Front remains a party with extreme right militants and culture."

MARKETS REACT

Jitters about the French election hit financial markets on Monday after polls tightened, with support growing for far-left candidate Jean-Luc Melenchon - who, like Le Pen, wants a referendum on the country's membership of the European Union.

France's borrowing costs hit their highest level compared with Germany's for six weeks while the euro edged lower against the dollar.

Polls have for weeks shown Le Pen and Macron topping first-round voting and qualifying for the May 7 run-off that Macron is predicted to win easily.

But there has been a recent surge by the Communist-backed Melenchon, who would take France out of NATO, and support for conservative Francois Fillon, whose campaign has struggled as he fights nepotism allegations, has stabilised.

An Opinionway survey on Monday showed Le Pen winning 24 percent in the first round, ahead of Macron on 23 percent, Fillon on 19 and Melenchon on 18.

"Two weeks ago, investors were starting to get comfortable with the idea of a Macron victory, but with the rise of Melenchon this is on the verge of becoming a four-horse race," said Rabobank strategist Lyn Graham-Taylor.

France has long struggled to come to terms with its role under the collaborationist Vichy regime during World War Two.

Altogether 76,000 Jews deported from France were killed.

In 1995, then President Jacques Chirac recognised that the French state shared responsibility for deporting Jews to Nazi death camps, the first time a post-war French head of state had fully acknowledged France's role.

Socialist President Francois Hollande in 2012 described the 1942 mass arrest as "a crime committed in France, by France."

Le Pen issued a statement late on Sunday saying she considered the French state was in exile in London during the occupation and that her stance "in no way exonerates the effective and personal responsibility of the French people who took part in the horrible Vel d'Hiv roundup and in all the atrocities committed during this period." (Reporting by Ingrid Melander, Cyril Camu, Marine Pennetier, Sophie Louet, Adrian Croft, Jeffrey Heller; Editing by Richard Balmforth and John Stonestreet) ((adrian.croft@thomsonreuters.com;))