The protests in Turkey have accomplished the seemingly impossible: uniting fans of Istanbul's three bitterly rival soccer teams.

Normally, there is no love lost between supporters of Fenerbahce, Galatasaray and Besiktas. Ferocious confrontations are common, and Galatasaray's stadium has earned the nickname "Hell" because of the intimidating atmosphere for opposing teams.

Violence has even been deadly on occasion. In mid-May, a 20-year-old Fenerbahce fan was stabbed to death by two people wearing Galatasaray shirts after a match.

All that changed on May 31, when a violent police crackdown on a peaceful protest against a redevelopment plan that would have turned a park in the city's main Taksim Square into buildings galvanized tens of thousands of Turks into action.

Before the weekend was out, protesters from all walks of life had thronged into the square and the accompanying Gezi Park, to fight off the police. Barricades were erected, the injured treated in their dozens by fellow protesters and volunteer doctors before being carried to hospitals.

Soccer fans, well versed in battling police and dealing with tear gas and water cannon, became instrumental in helping those overcome by the chemicals which blanketed the area, and organizing barricades. Sworn enemies who usually display nothing but hatred and contempt for each other have united as one, throwing their arms around each other and chanting together.

Carsi, a group of die-hard Besiktas fans, played a particularly prominent role, and their involvement propelled them to mini-stardom in the protests.

"There were times when Carsi members distributed gas masks to people and gave first aid to people who were injured ... And there were times they called on people to remain calm and to clean the place up, and they acted as a bridge between police and protesters," said Melis Alphan, a columnist for the daily Hurriyet.

Carsi, she said, became a "hero" of the protests.

Within days, an incredible sight had appeared. Pinned up on a wall next to a mountainous improvised barricade made of bricks and metal railing hung a new flag combining the colors of all three teams: Black and white for Besiktas, yellow and red for Galatasaray and Fenerbahce's yellow and dark blue. In the center, a new symbol that combined the three teams' logo, with the words: "Istanbul United. Since 31 May 2013."

On Saturday night, soccer fans joined tens of thousands of protesters in Taksim Square in one of the largest gatherings in the protests so far. They sang and danced, standing on the top of a building holding dozens of red flares that lit up the night sky. Earlier, thousands of Besiktas fans had marched through central Istanbul, with a group of Galatasaray supporters bringing up the rear of their raucous march, before joining up with Fenerbahce fans, who had crossed the Bosphorus on a ferry from the city's Asian side.

"It was a great proud moment for us when Fenerbahce supporters joined us," said Sercan Emiroglu, a 30-year-old Besiktas fan who is a sympathizer of Carsi and was at the march. One Fenerbahce banner elicited particular praise. It read: "We would sacrifice everything for Carsi."

The recent protests have been the most widespread Turkey has seen in decades, spreading from Istanbul to a total of 78 cities. They quickly morphed into a general denunciation of what many called Prime Minister Recep Tayyip Erdogan's increasingly authoritarian manner, and his attempt to impose conservative Muslim values on a country with secular laws.

On Monday, Turkey's opposition party leader accused Erdogan of escalating tensions and dragging the country "into the fire" as anti-government protests that have led to three deaths hit their 11th straight day.

Erdogan headed a Cabinet meeting to discuss the protests, the first serious challenge to his 10-year rule. On Sunday, he made a series of fiery speeches in three cities, saying the government's patience was running thin, demanding an end to the protests and threatening to hold those who don't respect his government to account. He has also called for major pro-government rallies in Ankara and Istanbul next weekend, apparently aiming to intimidate the protesters by showing that he, too, can get large numbers out on the street.

Protesters on Monday continued to occupy the park in Taksim Square. Police in Ankara again removed tents from a small park where protesters have gathered to show of support for the Istanbul protesters.

The unity of rival soccer fans during the protests has astonished many.

But Carsi, the group of Besiktas fans, rarely shies away from stating its views on social issues, and has been outspoken on subjects as diverse as police behavior to anti-nuclear protests.

"Their slogan 'Carsi opposes everything' is a reflection of their extraordinary, contrarian spirit," prominent sports writer Bagis Erten said. "Their ability for irony and sense of humor has perfectly matched with the spirit of these protests."

After the bitterly polarized atmosphere of soccer in Turkey, marred by riots, clashes with police and the stabbing, "the soccer world is now waking up," Erten said.

"Now, things have been balanced as they should be," he said. "The atmosphere of unfairness brought everybody together... This is a priceless experience."

Kerim Yilmaz, the 26-year-old leader of Besiktas' soccer fans in Ankara, said during a recent demonstration, "we are against injustice, just because we are Besiktas fans."

"Our freedoms are being limited. We do not want our green areas to be used for shopping malls. We all want to live freely. We are here to defend our freedom."

Of course, unity between such bitter rivals is unlikely to last forever. And the cracks have already begun to appear.

Galatasaray's fan group, ultrAslan said over the weekend that while it participated in the initial protests, it didn't want to become involved in politics.

"Last week, a series of demonstrations were organized by people who have environmental sensitivities to prevent the destruction of Gezi Park, and we organized a march to support these demonstrations as ultraAslan," the group said in a statement posted on its website.

Since then, "we have been saddened to see political action has begun to emerge along with the Gezi park protests. Attempts aiming at raising the issue to a political level and attempts to hijack the protests by some movements are unacceptable for us."

While it respects those protesting to save the park, "no one should attempt to categorize and use ultrAslan in favor of a political movement."


Burak Sayin in Istanbul contributed to this report.