By JOE PARKINSON and EMRE PEKER
ISTANBUL—Violence between protesters and police erupted and spread for a second consecutive day in Istanbul on Sunday, as Prime Minister Recep Tayyip Erdogan sought to regain the political agenda by staging a massive rally, after ejecting protesters from their park encampment the previous day.
Meanwhile, there was renewed fighting in Ankara and five unions called a general strike for Monday. There was also some violence between supporters and opponents of the government.
The second straight day of clashes flared through pockets of Istanbul as the government widened a crackdown it launched against protesters late Saturday, when it cleared a protester encampment from Gezi Park, the symbolic heart of demonstrations entering their 18th day.
A short distance away, Mr. Erdogan on Sunday took the stage to address a rally estimated at under 300,000 supporters of the governing Justice and Development Party, or AKP, and declared victory over the protests in the biggest show of political force since the protests began. The premier chided the protesters for rejecting an offer he had made to mollify them.
Five people have been left dead from 18 days of protests and more than 5,000 injured.
While the park initially was just the venue of an environmental sit-in to save it from development, authorities' efforts to disperse protesters with tear-gas and water cannons unleashed a broad-based coalition pouring out to protest what they see as Mr. Erdogan's increasingly encroachment into their lives.
On Sunday, protesters built barricades and faced off against police, who the day before were for the first time joined at key intersections by military police. Police fired tear gas and water cannon at protesters seeking to march toward the park.
More than 200 protesters were detained, according to Amnesty International. The Turkish Medical Association said a number of medical staff volunteering to treat injured protesters had been arrested, but Istanbul Governor Huseyin Avni Mutlu, insisted no doctors were detained.
Mounting a verbal assault on the demonstrations, which he said were organized by fringe groups and the main opposition Republican People's Party leader Kemal Kilicdaroglu, Mr. Erdogan told his rally that by occupying the park, protesters attacked the broader society's freedoms.
But Mr. Erdogan's decision to strike a more definitive blow against protesters this weekend appeared to have partially backfired on Sunday as demonstrations continued and five of Turkey's largest trade unions and associations—with a combined membership of 860,000 workers, doctors, dentists, engineers and architects—called a general strike for Monday, in solidarity with the protesters.
Clashes continued in Ankara, where police fired tear gas and water cannons to stop a march on central Kizilay Square that was to commemorate the death of a demonstrator who died from a bullet to his head during clashes with police last week.
And in another development, there were reports of street clashes between supporters and detractors of the government, an ominous sign that the unrest is pulling in factions of the civilian population, adding stress to Turkey's tense societal fault lines.
"The crack Erdogan has created in Turkey is very interesting because this educated middle class is clashing with the government for the first time. If these tensions continue, the uncertainty will negatively impact the political system and the economy," said Hakan Yilmaz, a political scientist at Bogazici University in Istanbul.
In the city of Konya, where Mr. Erdogan's party enjoys overwhelming support, a small group of demonstrators was attacked by a group of people.
In Istanbul, a small group of people attacked a local chapter of the main opposition party, CHP, trapping lawmakers inside, eyewitnesses said. Television footage also showed dozens of men wielding sticks and chanting "Recep Tayyip Erdogan" on the city's main pedestrian thoroughfare.
And antigovernment demonstrators crossing the Bosporus from the Asian side to the European shore of Istanbul to march to Taksim Square engaged in shouting matches and cross-faction chants with other boats ferrying Mr. Erdogan's supporters to the prime minister's rally, eyewitnesses said.
The fresh violence came after almost a week of relative calm in Istanbul. A nonviolent solution briefly appeared possible Friday when Mr. Erdogan offered to put his plan to develop the park up to a public vote in Istanbul if the government prevails against legal challenges to halt the project.
But Taksim Solidarity, an umbrella group of protest organizers, rejected the deal on Saturday because, it said, Mr. Erdogan refused to recognize broader democratic grievances and demands including the release of everyone detained in connection with the demonstrations.
And as anger raged among protesters on Sunday night, there was little sign the demonstrations would end. "This isn't just about the Gezi Park. We've opened our eyes," said Tugce Demir, a 24-year-old who works in advertising and has been at the antigovernment protests since they started May 31. "This is our reaction to a decade of this government's policies."