Turkish President Tayyip Erdogan has ordered the closure of more than 1,000 private schools and extended the period in which some suspects can be detained without charge, in his first decree since declaring a three-month state of emergency.

Key points: Erdogan vows to bring to justice supporters of the Gulenist 'terrorist' movement

Erdogan vows to bring to justice supporters of the Gulenist 'terrorist' movement Gulen's nephew is detained in Turkey for questioning

Gulen's nephew is detained in Turkey for questioning State of emergency allows the president to pass laws without initial parliamentary support

Mr Erdogan declared the state of emergency late on Wednesday saying it would enable authorities to swiftly and effectively root out supporters of last weekend's failed military coup in which at least 246 people were killed.

The state of emergency allows the president and Government to pass laws without first having to win parliamentary support and also allows them to curb or suspend rights and freedoms as they deem necessary.

Turkish authorities have already launched a series of mass purges of the armed forces, police, judiciary and education system, targeting followers of a US-based Muslim cleric, Fethullah Gulen, whom Mr Erdogan has accused of masterminding the failed coup.

The reclusive 75-year-old Mr Gulen denies the charge.

On Saturday (local time), state media reported that one of Mr Gulen's nephews, Muhammed Sait Gulen, had been detained and would be taken to Ankara for questioning.

Among possible charges that could be brought against him is membership of a terrorist organisation, the Anadolu news agency said.

It is the first time a relative of Gulen has been reported detained since the failed coup.

Erdogan signs decree to crack down on Gulen

The first decree signed by Mr Erdogan authorises the closure of 1,043 private schools, 1,229 charities and foundations, 19 trade unions, 15 universities and 35 medical institutions over suspected links to the Gulen movement, the state news agency Anadolu reported.

Mr Erdogan has also approved the extension of the period in which certain suspects can be detained to 30 days from a maximum of four days, Anadolu said.

The period has been extended to facilitate a full investigation into the coup attempt.

Parliament must still approve the decree but requires only a simple majority, which the ruling AK Party, founded by Mr Erdogan and in power in Turkey since 2002, commands.

In an address to lawmakers late on Friday Mr Erdogan vowed to bring to justice supporters of the Gulenist "terrorist" movement.

He also inspected damaged parts of the parliament building in Ankara that were strafed by the coup plotters during last weekend's violence.

Meanwhile, US Treasury Secretary Jack Lew said the United States strongly supported the Turkish Government and urged it to investigate the failed coup in a way that reinforced public confidence in democratic institutions and promotes economic stability.

Mr Lew made the comments in a meeting with Turkish Deputy Prime Minister Mehmet Simsek on the sidelines of a G20 meeting in China, according to a statement from the Treasury.

Mr Lew said the Treasury was closely monitoring the situation and the impact on the Turkish economy.

Reuters