Turkish authorities rounded up nearly 3,000 suspected military plotters on Saturday and ordered thousands of judges detained after thwarting a coup by rebels using tanks and attack helicopters to try to topple President Tayyip Erdogan.

For several hours overnight on Friday violence shook Turkey's two main cities, as the armed faction which tried to seize power blocked a bridge in Istanbul and strafed the headquarters of Turkish intelligence and parliament in Ankara.

At least 265 people were killed. An official said 161 of them were mostly civilians and police officers, while the remaining 104 were coup supporters.

But the coup attempt crumbled as Erdogan rushed back to Istanbul from a Mediterranean holiday and urged people to take to the streets to support his government against plotters he accused of trying to kill him.

"They will pay a heavy price for this," said Erdogan, launching a purge of the armed forces, which last used force to stage a successful coup more than 30 years ago. "This uprising is a gift from God to us because this will be a reason to cleanse our army."

Among those detained were top military commanders, including the head of the Second Army which protects the country's borders with Syria, Iraq and Iran, state-run Anadolu news agency said.

Hundreds of soldiers were held in Ankara for alleged involvement in the coup, leaving police stations overflowing.

Some had to be taken under armed police escort in buses to a sports stadium. Reuters footage showed some of the detainees, handcuffed and stripped from the waist up, sitting on the floor of one of the buses.

The government declared the situation under control, saying 2,839 people had been rounded up, from foot soldiers to senior officers, including those who formed "the backbone" of the rebellion.

Authorities also began a major crackdown in the judiciary over suspected links to U.S.-based cleric Fethullah Gulen, removing from their posts and ordering the detention of nearly 3,000 prosecutors and judges, including from top courts.

Erdogan has blamed the coup on supporters of Gulen, who he has frequently accused of trying to foment uprising in the military, media and judiciary.

Ten members of the High Council of Judges and Prosecutors and two members of the Constitutional Court have already been detained, officials said.

PHOTO CAPTION

Supporters of Turkish President Tayyip Erdogan wave national flags as they gather at Taksim Square in central Istanbul, Turkey, July 16, 2016.

Reuters