Coup Attempt: State of emergency declared in Istanbul - Turkey

Unidentified helicopters are reportedly being spotted over the city, two days after a coup attempt.

FILE: People take cover during clashes near the Bosphorus bridge as Turkish military clash with people at the entrance to the bridge in Istanbul. Picture: AFP.

ANKARA - A state of emergency has been imposed in the Turkish city of Istanbul as armoured vehicles and an additional 1,800 special police forces are being deployed to key locations.

Unidentified helicopters are reportedly being spotted over the city, two days after rebel aircraft were used in a military coup attempt to attack police and government buildings.

President Tayyip Erdogan has ordered the deployment of at least a dozen F-16 fighter jets to monitor Turkish airspace.

The alert comes on the heels of reports that at least 42 military helicopters went missing during the coup turmoil.

There's speculation they might be used in another attempt to seize power by coup plotters.

The Turkish government's official line, however, is that the coup attempt has been squashed and since Saturday, there have been mass purges in the military and judiciary, with more than 6,000 people arrested, including generals, judges and prosecutors.

The mass arrests have prompted a worried response from European leaders, who are calling on Ankara to uphold democracy and the rule of law.

There is growing concern that Erdogan will use the failed coup attempt to entrench his rule.

He's openly called the coup attempt a "gift from God," that allows the government to "cleanse the army"once and for all.