A building housing French presidential candidate Marine Le Pen's campaign headquarters was hit by an arson attempt on Thursday, firefighters and police said, with only minor damage caused.

Firefighters were called around 2:40 am (0040 GMT) to the ground floor offices of an insurance company on the upmarket Rue du Faubourg Saint-Honore in central Paris.

A fire service spokesman said the fire was "quickly brought under control" and damaged only the door and a doormat.

The upper floors of the building, on one of the French capital's most exclusive streets close to the president's Elysee Palace official residence, house the campaign offices of far-right National Front (FN) leader Le Pen.

The anti-globalisation, anti-EU Le Pen is neck-and-neck with centrist Emmanuel Macron in polls for the first round of the election on April 23.

A police source said the cause of the fire was "not natural and probably criminal", adding that the graffiti slogan "FN vs KLM" was found nearby.

A group calling itself "Fight Xenophobia" contacted AFP to claim the attack, which it said was carried out with "Molotov cocktails".

The caller, who refused to give a name, also claimed to have carried out a similar attack on a far-right newspaper and said the action would continue until the election.

Source: AFP