In a chaotic and crumbling former public washhouse in a rundown district of northern Paris, Inna Shevchenko was explaining how a large leather punchbag hanging from the rafters might be used by the foot soldiers of a new generation of feminists.

As she prepared to welcome recruits to the Ukrainian-based feminist group Femen's first "international training camp", it was clear that the instruction would not be all ideological. The talk was of "war", "soldiers", "terrorism" and "enemies". Was it not curious, one French journalist asked, that Inna and her warriors had adopted the language of combat, traditionally a male domain, to describe their mission?

Was it not also inconsistent, another asked, that the new feminists were using nakedness to rail against female exploitation? In a week that had seen the banning of photographs of a topless Duchess of Cambridge, it was certainly topical.

"Ah, but we have a different idea; we are talking about peaceful war, peaceful terrorism," Inna said. "We are taking off our clothes so people can see that we have no weapons except our bodies. It's a powerful way to fight in a man's world. We live with men's domination and this is the only way to provoke them, the only way to get attention.

"We don't hide our bodies, we don't hide our faces, we confront our enemies face to face. We look them in the eyes and we have to be well prepared physically for that."

There was, she explained patiently, no contradiction in going topless or naked to protest against what they view as the three main evils of a global "patriarchal society": sexual exploitation, dictatorship and religion. Protesting naked, as Femen's slogans insist, is liberté, a reappropriation of their own bodies as opposed to pornography or snatched photographs which are exploitation.

On a less intellectual level, taking their clothes off ensures a lot of publicity.

"There is an ideology behind protesting topless, but we quickly realised that if we took our tops off and screamed loudly it was a good way to get attention," Alexandra Shevchenko, one of Femen's founders, said. "It works. Of course, people talk about our nakedness, but they are also listening to our message."

She added: "Believe me, it is really difficult for me to take my clothes off and stand in a public place. But this is the fight, and the fight is never easy."

The Femen movement was created in Ukraine in 2008 to protest against sexism, prostitution and the exploitation of women in the former Soviet state. Inna, 22, second daughter of an army officer, and a journalism graduate, took off her top and joined the protests, a decision that would cost her a well-paid job as a press officer at Kiev town hall. In August, she fled Ukraine after a well-publicised stunt in which she wielded a chainsaw semi-naked to chop down a large wooden Orthodox cross in support of the jailed Russian feminists Pussy Riot: "Afterwards I was followed for three days by the secret services. In fact they're not very secret, they like you to know they are following you to make you scared. One morning they tried to break into my apartment. I thought it was a sign I was in danger. I wasn't scared about being in prison. I have already been in prison many times, but there are worse things."

An open invitation from a group of feminists in France brought her to Paris, where Femen has set up camp in the Lavoir Moderne Parisien, in Paris's poor and ethnically mixed Goutte d'Or district. In his 1877 novel L'Assommoir, Emile Zola described the Lavoir Moderne, then a state-of-the-art public washroom, as an "immense hangar, with its flat ceiling, and open beams sitting on steel pillars closed off with large clear windows".

After closing in 1953, it began a second life as a community theatre, now under threat and in financial difficulty after a property developer acquired the building with a view to turning it into flats.

On the first floor, high above where the old zinc washing vats would have steamed, a vast airy room is plastered with Femen campaign slogans: "Nudity is freedom", "Let's get naked", "I am a woman, not an object".

If the male journalists and photographers who have beaten a path here since Femen announced its training camp are disappointed to find the girls fully dressed in the international uniform of jeans and T-shirts, they have the good grace not to show it.

Outside, on the streets of Goutte d'Or, the three tall, beautiful women cut an incongruous path through the veiled and headscarf-wearing women of the large local Muslim community, weaving their pushchairs through the roadworks. Femen's "Better naked than the burqa" campaign has made few inroads here.

"The decision to bring the fight to France and open a training centre was a French initiative, an invitation from French feminists who sent us a message saying they needed us," said Inna.

"Before then we thought of France as a first world and already feminist country that didn't really need us. Since arriving, I have met many Frenchwomen and they say they need to start the fight again. We are bringing a new face, new blood, a new fight to feminism."

She added: "Classical feminism is like an old sick lady that doesn't work any more. It's stuck in the world of conferences and books. We have the same ideas as the classical feminists, what is different is the form of fight. We fight in a way that will attract young women to the ideology again.

"Early feminists fought for the right for women to wear trousers and jeans and won. Now we can wear trousers and jeans, but when a woman speaks in parliament, do the men listen? It's still a world dominated by men, where women are slaves and where women still do not earn the same or have the same opportunities. So we have to start again. It's the clothing fight all over again."

To that end, Inna is staying in Paris to give her new feminist recruits their "physical and ideological training", while Femen militants Alexandra, 24, and Oxana Shachko, 25, are returning to Kiev, where a similar camp will be established. A third is planned for Brazil, where Femen has a large following, in the runup to the 2016 Olympic Games.

"Soldiers will be born here, but they will not be French soldiers. They will be feminist soldiers, international soldiers," said Inna. "Women in every country need Femen."

Back to the big leather punchbag hanging from the rafters, and Inna admits that the training sessions will not be entirely pacifist. "Feminism should be provocative," she adds. "There's no other way for women to get attention. It's the only action left to us. So the training will be moral but also physical. You have to be in good shape, because at protests you may need to run away or attack the police or jump on a building or a car."

The French riot police in their "robocop" outfits have been warned.