* Russia warns of U.S. intervention in Venezuela

* Russia, Turkey and China back incumbent Maduro

* EU offers supportive words for opposition (Adds EU parliament, other countries)

MOSCOW/BRUSSELS, Jan 24 (Reuters) - Russia accused the United States on Thursday of trying to usurp power in Venezuela and warned against military intervention, putting it at odds with Washington and the EU which backed protests against one of Moscow’s closest allies.

Venezuelan opposition leader Juan Guaido declared himself interim leader on Wednesday, winning the support of Washington and parts of Latin America. That prompted socialist President Nicolas Maduro, who has led the oil-rich nation since 2013, to sever diplomatic ties with the United States.

The prospect of Maduro being ousted is a geopolitical and economic headache for Moscow which, alongside China, has become a creditor of last resort for Caracas, lending it billions of dollars as its economy implodes. Moscow has also helped its military and oil industry and provided wheat.

Russia on Thursday accused Washington of stoking street protests and called Maduro the legitimate president.

“We consider the attempt to usurp sovereign authority in Venezuela to contradict and violate the basis and principles of international law,” Kremlin spokesman Dmitry Peskov said.

The Russian Foreign Ministry said an outside military intervention could have “catastrophic consequences.”

Turkish President Tayyip Erdogan offered support for Maduro too. “My brother Maduro! Stand tall, we stand by you!” presidential spokesman Ibrahim Kalin, writing on Twitter, quoted Erdogan as saying.

China also said it supported efforts to protect Venezuela’s independence and stability.

EU SUPPORT FOR OPPOSITION

The European Union, which has imposed sanctions on Venezuela and boycotted Maduro’s swearing-in for a second term earlier this month, took a more nuanced tack.

Although it stopped short of following Washington and recognising Guaido as interim president, it appealed for him to be protected and appeared to support calls for a peaceful transition of power away from Maduro.

“The people of Venezuela have massively called for democracy and the possibility to freely determine their own destiny. These voices cannot be ignored,” the 28-nation bloc said.

The biggest group in the European Parliament, the centre-right European People’s Party, said it recognised Guaido as interim president and would call on the whole parliament to do so next week as a senior lawmaker urged Maduro to quit.

French President Emmanuel Macron saluted Venezuelans marching for freedom. Germany, Switzerland and Portugal called for free elections, and Spanish Prime Minister Pedro Sanchez told Guaido he supported the Venezuelan parliament.

Britain said Maduro’s 2018 election was neither free nor fair and expressed support for Guaido.

There was nervousness about how far the EU could go however.

“The problem is that we can’t recognise somebody who was not elected democratically,” said one EU diplomat. “That would create a dangerous precedent for any other person who would want to proclaim themselves the president of something.”