An arson attempt caused minor damage to a Paris building where French presidential candidate Marine Le Pen has her campaign headquarters.
Ms Le Pen accused leftist groups of carrying out the attack.
A police source said the ground floor of the central Paris building was targeted and graffiti mentioning Ms Le Pen's National Front was found nearby.
The source said the damage was likely the result of a criminal act and not an accident.
France’s interior minister Matthias Fekl condemned the attack. “These are unacceptable acts, the democratic debate must take place in the ballot box,” he told RTL radio, without giving any details about the attack itself.
“We have been in touch with the National Front candidate’s team since last night and will see with them if it is necessary to strengthen security procedures.”
Ms Le Pen told France 2 television she believed a leftist group was responsible, but she gave no detail and did not say why she believed one such group was responsible.
“I assume this is due to a small leftist group...These groups act in total impunity,” she added, saying that the government should dissolve them.
AFP said a group calling itself “Combat xenophobia” contacted them to claim responsibility for the arson attempt.
Reuters