(Adds markets background)
* Thousands of protesters outside parliament building
* Yanukovich says China visit still on despite turmoil
* Protesters blockade government, some strike
* Opposition calls for no confidence vote
By Thomas Grove
KIEV, Dec 3 (Reuters) - Thousands of pro-EU protesters calling for the resignation of Ukrainian President Viktor Yanukovich gathered outside parliament on Tuesday with opposition leaders pressing for a vote of no-confidence in his government.
Only days after a massive rally that brought 350,000 protesters into central Kiev, Yanukovich is set to travel to China, leaving the country plunged into crisis by his decision to spurn a landmark deal with the European Union and boost ties with Ukraine's Soviet master Russia.
In addition to political opposition, Yanukovich is under pressure from international markets, increasing the risk of a financial crisis that could force his hand.
Ukraine's currency and bonds have come under pressure, along with share prices, and the central bank was forced to assure people their savings were safe and there was no need for panic withdrawals.
The cost of insuring Ukraine's debt against default has risen to its highest since September, while the government must find billions to meet debt repayments and the cost of gas imports next year.
Outside parliament, several thousand protesters holding EU and Ukrainian flags stood face to face with riot police. Prime Minister Mykola Azarov accused the opposition of planning to seize the building.
Protesters had blocked the entrances to the main government building on Monday, and Azarov said the government could not perform its basic functions, which could affect the payment of pensions and salaries.
"This has all the signs of a coup d'etat. This is a very serious matter," Interfax news agency quoted him as telling the ambassadors of the EU, United States and Canada.
Parliamentarian Hannah Herman, from Yanukovich's Party of Regions, said there was a possibility that some members of the party could vote against Yanukovich's government.
Deputies were due to debate whether to hold a no-confidence vote. The opposition needs at least 226 votes to get the confidence motion on the agenda, and the same again to pass it.
In Kiev's Independence Square protesters set up tented camps in preparation for a long campaign against Yanukovich's last-minute decision to reject the free trade deal, which had been due to be signed on Friday.
On Monday, demonstrators halted traffic and called a general strike, seeking to force Yanukovich from office after massive demonstrations at the weekend, the biggest since the pro-democracy "Orange Revolution" of nine years ago.
The United States said violence by the authorities against protesters on Saturday was unacceptable that reports of media representatives being targeted were "disturbing".
With temperatures dropping well below zero, the numbers of protesters have dropped sharply, and Yanukovich clearly felt the security situation was under control when he announced he would stick to a plan to travel on Tuesday to China, from which he is seeking loans and investment to avert a debt crisis.
But some felt leaving was unwise nevertheless.
"It is a very bad time to go abroad. The president's absence may make talks with the opposition much more difficult," said Ukrainian political analyst Gleb Vyshlinsky.
Russia wants to draw Ukraine into a Moscow-led customs union and prevent it moving closer to the EU, a move that would signal a historic shift towards the West and away from Kiev's former Soviet masters in Moscow.
But the tug-of-war between Brussels and Moscow for influence in Ukraine has so far done little to alleviate its looming debt crisis and the China visit will involve the signing of at least 20 economic and trade agreements.
"Yanukovich is trying to show that the European Union and Russia are not the only possible partners for Ukraine," said Volodymyr Fesenko of Ukraine's Penta think-tank.
However, he said Beijing may now demand assurances over Ukraine's political and economic stability, adding: "Ukraine is unlikely to secure direct financial aid (from China)."
Beijing has already provided the former Soviet republic with loans worth $10 billion, but the government must find more than $17 billion in 2014 to meet gas bills and debt repayments. (Additional reporting by Pavel Polityuk; editing by Richard Balmforth and Giles Elgood)