President Recep Tayyip Erdogan pledged yesterday the "cleansing" of state institutions will continue, as around 6,000 people were arrested and the military announced the formal end of the failed coup.

The plotters "have nowhere to flee," Erdogan said in a fiery speech delivered at a funeral ceremony for several people killed during last Friday night's coup attempt by a group within the armed forces. He said a "cancer" had spread but vowed no pause in the counterstrike.

Erdogan blames Fethullah Gulen, a US-based, Turkish-born preacher and one-time ally turned rival accused of running a "parallel state."

Gulen strongly denies any involvement in the coup, which left 290 people dead, including more than 100 alleged mutineers, Turkey's Foreign Ministry said yesterday, and more than 1,100 injured.

Erdogan is demanding Washington extradites the preacher, though Turkey has not presented yet direct proof of Gulen's immediate involvement.

US Secretary of State John Kerry (photo) told US broadcaster ABC he expects to hear from Turkey's Justice Ministry soon on a formal request and would consider an extradition application if it meets legal standards.

Fresh arrests continued to be announced throughout the day, and there was a stand-off with warning shots fired at an airport in Istanbul, which ended with 11 alleged pro-coup soldiers surrendering.

Photos emerged of jailed alleged coup leaders and soldiers involved in the takeover of bridges and an airport, and attacks on key buildings. Some showed the individuals bloodied in their cells and in-line ups at police stations.

Akin Ozturk, a former commander of Turkey's Air Force, was among detainees pictured with his ear bandaged. One official described him as a "mastermind" of the plot.

The Justice Ministry said about 6,000 people were arrested. Among them were nearly 3,000 soldiers, officials said, including at least 29 generals and dozens of colonels and other high-ranking officers.

The heads of two of the four land forces are in detention.

Arrest warrants were issued for 250 judges and prosecutors, and 2,745 judges were dismissed from their posts over the weekend. An arrest warrant was issued for a top military aide to Erdogan.

Incirlik airbase, used for the US-led coalition bombing campaign against Islamic State extremists in Syria and Iraq, was again opened for operations after being shut for a day after the coup attempt.

Six F-16 aircraft were hijacked by the plotters during the coup attempt and used to attack key buildings, including Parliament, which suffered serious damage to the facade, according to government officials.

General Bekir Ercan Van, commander of the airbase in southern Turkey, was arrested with 10 of his soldiers.

The Anadolu news agency reported last night that 14 soldiers in Marmaris, where Erdogan was on holiday at the time of the putsch, had been arrested. The group had allegedly been responsible for a planned attack on Erdogan's hotel, and he later described a bombing there after his departure.

Erdogan said he would discuss with opposition parties in Parliament about the possibility of capital punishment for those who carried out the failed coup attempt.

"In a democracy, you cannot ignore the demands of people," he said, citing chants from supporters calling for the death penalty.

Capital punishment has not been used in Turkey since 1984 and was abolished in 2004.

Parliament convened in Ankara on Saturday, hours after the coup was crushed, in a rare show of unity across party lines.

Increasingly authoritarian

The opposition, often targeted by the government, used the opportunity to urge a strengthening of democracy. Erdogan has been accused of becoming increasingly authoritarian in his more than 13 years in power.

Some citizens and analysts have expressed deep concerns about the scale of the crackdown.

Turkey's security services asked citizens to send screenshots and report social media users who spread support of "terrorist activities", warning that "black propaganda" was being circulated online.

"Erdogan repressive instincts were amply evident before the coup attempt. The coup isn't going to make him change his tune. If anything, he's simply going to turn up the volume," said Professor Howard Eissenstat of St Lawrence University.

Eissenstat warned that a successful coup would have been worse and could have led to "civil war" among the different branches of the security services.

On Twitter, the German foreign minister said the coup attempt was a "wake-up call for Turkish democracy," and said he hoped that the democratic unity shown in the face of the incident can help the country overcome its deep divisions.

In the early hours of the coup attempt, Erdogan had called his supporters to take to the streets against the military elements - using social media and Internet platforms - and it was answered en masse, a key factor in the government keeping control.

Intelligence services chief Hakan Fidan told local paper Milliyet that the government had become fully aware of the impending coup attempt hours before it was launched. Other evidence suggests the government was able to survive by being prepared.

Erdogan urged people to continue to stay on the streets. He himself went out to the crowds a couple of times and attended funerals throughout the day. Crowds remained on the streets late last night in Istanbul, Ankara and other major cities.

The Turkish Army formally declared the coup attempt crushed, blaming "traitors," whom it vowed to severely punish.

- dpa