TURKEY'S armed forces said tonight they have "fully seized control" of the country, citing rising autocratic rule and increased terrorism.

The military statement read on state TV came after gunfire was heard outside military headquarters, fighter jets buzzed over the capital and vehicles blocked two major bridges in Istanbul.

The prime minister, however, said there was an "attempt" at a coup.

Soldiers blocked entry to Ataturk Airport where four tanks were stationed, according to the private Dogan news agency. Two other tanks and a military vehicle were stationed in front of the VIP terminal. The report said soldiers had entered the tower and stopped all flights.

President Recep Tayyip Erdogan has urged citizens to take to the streets in a show of support for the government.

Speaking to CNN-Turk through FaceTime, he called the actions by the military "an attempt at an uprising by a minority within our armed forces".

The president's office refused to disclose Mr Erdogan's whereabouts, saying he was at a secure location.

Mr Erdogan said "I don't believe this coup attempt will be successful.

"There is absolutely no chain of command here. Right now the chain of command has been put on hold."

The military said it seized control "to reinstall the constitutional order, democracy, human rights and freedoms, to ensure that the rule of law once again reigns in the country, for the law and order to be reinstated".

The military statement went on to say that "all international agreements and commitments will remain. We pledge that good relations with all world countries will continue".

Premier Binali Yildirim said that a group within the military has engaged in what appeared to be an attempted coup.

He told the private NTV television: "it is correct that there was an attempt", when asked if there was a coup.

Mr Yildirim did not provide details, but said Turkey would never allow any "initiative that would interrupt democracy".

"We are focusing on the possibility of an attempt (coup)," Mr Yildirim said.

"There was an illegal act by a group within the military that was acting out of the chain of military command. Our people should know that we will not allow any activity that would harm democracy."

Military jets were heard flying over Ankara and Istanbul. Gunfire was heard outside Turkey's military headquarters in Ankara, while media reports said ambulances were seen out front.

"There are certain groups who took the arms trusted to them by the state and pointed them toward state employees," Mr Yildirim said.

"We shall determine soon who they are. Our security forces have acted against these groups."

The Dogan news agency said traffic on the Bosphorus and Fatih Sultan Mehmet bridges was blockedby military vehicles.