Switzerland said Thursday it was prepared to freeze any funds Ukraine's ousted president Viktor Yanukovych might have in Swiss banks. The Swiss government has decided "in principle to freeze any possible funds Mr Yanukovych may have in Switzerland", foreign ministry spokesman Pierre-Alain Eltschinger told AFP in an email. The full decision, which would be published Friday, obliged Swiss banks to show increased vigilance when it comes to Ukrainian funds, he added. Asked whether Yanukovych or his entourage would be blocked from receiving visas to Switzerland, the foreign ministry spokesman would only say that "Switzerland is following very closely the situation in Ukraine." Yanukovych, who is wanted for "mass murder" after three months of protests against his rule spilled into clashes that left nearly 100 dead, said in a statement Thursday he was still Ukraine's head of state. It is unclear whether Yanukovych himself has funds in Switzerland, but his son Olexander opened a branch of his Management Assets Company (MAKO) in Geneva in late 2011. The 40-year-old dentist and businessman has amassed a personal fortune of around half a billion dollars (some 365 million euros) in the past three years alone, according to a report in the Swiss weekly L'Hebdo. His Ukrainian conglomerate reportedly controls nearly half of that country's coal production, and around a third of its electricity production and distribution. The Geneva branch of the business is run by a businessman of Uzbek origin, who also runs a firm called Partefina, listed with the same address That company is listed as a so-called "family office" -- a term used for firms specialising in the management of large family fortunes. According to L'Hebdo, Partefina is owned by Ukrainian billionaire Rinat Akhmetov, a supporter of Yanukovych who also has offices in Geneva. The oligarch opened a branch of his DTEK Holding business in the Swiss city. According to Swiss public broadcaster RTS, the branch's capital swelled from 100,000 Swiss francs ($113,000, 82,000 euros) to 49 million francs last December. Ukrainians demonstrated in the Swiss capital of Bern Wednesday to demand that Switzerland freeze any of Yanukovych's assets in the country. Demonstrators also gathered in front of the UN's European headquarters in Geneva Thursday, calling on Switzerland to "stop being passive."