Turkey's parliament has approved a three-month nationwide state of emergency in a 346-115 vote, parliamentary speaker Ismail Kahraman said.

President Recep Tayyip Erdogan announced the state of emergency on Wednesday night after a coup attempt launched by a faction of the military over the weekend left more than 260 people dead and 1,500 injured.

The government has since launched a drastic purge of state institutions, dismissing tens of thousands of civil servants and detaining about 9,000 people.

The coup attempt has also opened up a debate in Turkey on reinstating the death penalty as a form of punishment for plotters.

The emergency came into force on Thursday, almost a week after the rebel soldiers surged into the streets with tanks, bombing parliament and shooting protesters on a bloody night of turmoil.

Erdogan said it would allow Turkey to be cleared of "terrorists" linked to US-based Muslim preacher Fethullah Gulen, whom he accuses of orchestrating the failed coup from his leafy compound in Pennsylvania.

But Erdogan insisted democracy would "not be compromised" and lashed out at critics of the sweeping purge that has raised deep concerns about democracy and human rights in the key Nato member.

The extra powers, to restrict freedom of movement and other rights, were needed "to remove swiftly all the elements of the terrorist organisation involved in the coup attempt," Erdogan said.

Deputy Prime Minister Numan Kurtulmus said the special measures may only last up to 45 days, insisting that "we want to end the state of emergency as soon as possible".

Asked about whether the government may impose curfews, Kurtulmus said: "very clearly no. This is not a declaration of martial law."