* Istanbul streets quieter after night of unrest
* Police fire teargas in Ankara
* Ruling party rally set for Sunday
* Labour confederation calls national strike for Monday
Riot police fired occasional bursts of teargas in Istanbul on Sunday after a night of unrest to try to prevent anti-government demonstrators from regrouping ahead of a rally by Prime Minister Tayyip Erdogan's ruling party.
Bulldozers removed barricades and municipal workers swept the streets around the central Taksim Square, sealed off by police, after thousands took to the streets overnight following a raid by riot police firing teargas and water cannon to evict demonstrators from the adjoining Gezi Park.
Erdogan had warned hours earlier that the security forces would clear the area around the park - where protesters have been camped out for more than two weeks - before a ruling party rally on the other side of the city later on Sunday.
The government says the demonstrators are being manipulated by illegal groups seeking to sow instability.
"There are illegal groups there. Which country will turn a blind eye if a public space is occupied by a marginal group," EU Minister Egemen Bagis told Turkey's Kanal 24 television, citing Istanbul's governor as saying some of the protesters were believed to have been carrying guns.
"What did the prime minister say, he said people with good intentions should withdraw, we will deal with terrorists. By not withdrawing from there they created an impression that they are shielding terrorists," Bagis said.
Erdogan has long been Turkey's most popular politician, overseeing a decade of unprecedented prosperity, and his AK Party has won an increasing share of the vote in three successive election victories, but his critics complain of increasing authoritarianism.
While the protests pose no immediate threat to his government, they have tarnished Turkey's image as a haven of stability in a turbulent Middle East.
Panicked protesters fled into an upscale hotel at the back of the park during Saturday night's raid, several vomiting, as clouds of teargas and blasts from percussion bombs - designed to create confusion rather than injure - engulfed the park.
"We tried to flee and the police pursued us. It was like war," Claudia Roth, co-chair of Germany's Greens party, who had gone to Gezi Park to show her support, told Reuters.
The Gezi Park protesters, who oppose government plans to build a replica Ottoman-era barracks there, had defied repeated calls to leave but had started to reduce their presence in the park after meetings with Erdogan and the local authorities.
A similar police crackdown on peaceful campaigners in Gezi Park two weeks ago provoked an unprecedented wave of protest against Erdogan, drawing in secularists, nationalists, professionals, trade unionists and students who took to the streets in protest at what they see as his autocratic style.
The unrest, in which police fired teargas and water cannon at stone-throwing protesters night after night in cities including Istanbul and Ankara, left four people dead and about 5,000 injured, according to the Turkish Medical Association.
Riot police in Ankara fired teargas on Sunday to try to disperse hundreds of demonstrators blocking streets in the central Kizilay district, after first warning them through megaphones, a Reuters witness said.
Protesters took to the streets in several neighbourhoods across Istanbul after the raid on Gezi Park, ripping up metal fences, paving stones and advertising hoardings to build barricades and lighting bonfires of trash in the streets. Some chanted "Tayyip, resign."
"One million people to Taksim" - a call for more anti-government demonstrations later on Sunday - was a top-trending hashtag on Twitter overnight but many Istanbul streets were quiet after clashes died down in the hours before dawn.
There was a heavy police presence in some areas as bulldozers cleared barricades.
"We have our Istanbul rally tomorrow. I say it clearly: Taksim Square must be evacuated, otherwise this country's security forces know how to evacuate it," Erdogan had told tens of thousands of supporters at a rally in Ankara shortly before the police raided the park.
A main public-sector union confederation, KESK, which has about 240,000 members, said it would call a national strike for Monday, while a second union grouping said it was holding an emergency meeting to decide whether to join the action.
"The police brutality aims at clearing the streets of Istanbul to make way for Erdogan's meeting," said Oguz Kaan Salici, Istanbul president of the main opposition People's Republican Party. "Yet it will backfire. People feel betrayed."
Erdogan told protesters on Thursday that he would put the plans for Gezi Park on hold until a court rules on them. It was a softer stance after two weeks in which he called protesters "riff-raff" and said the plans would go ahead regardless.
But at the first of two rallies this weekend by his ruling AK Party, he reverted to a defiant tone, telling supporters on the outskirts of Ankara that he would crush his opponents in elections next year.
Erdogan has said the AK Party rallies in Ankara and Istanbul are meant to kick off campaigning for local elections next year and are not related to the protests, but they are widely seen as a show of strength in the face of the demonstrations.