Thousands of people in Turkey have turned out for a seventh night of protests which have so far seen more than 1,400 people detained, including students, journalists and lawyers.

The nightly unrest began last Wednesday when the city's Mayor Ekrem Imamoglu - who is seen as the President Recep Tayyip Erdogan's main political rival - was arrested on corruption charges.

Rights groups and the UN have condemned the arrests and the use of force by police on the protesters.

Imamoglu said the allegations against him were politically motivated, a claim the Turkish president has denied.

Speaking to a group of young people at a Ramadan fast-breaking meal in Ankara on Tuesday, President Erdogan urged patience and common sense amid what he described as "very sensitive days."

He added that people who want "to turn this country into a place of chaos have nowhere to go", and the path protesters have taken is "a dead end".

On Tuesday evening, thousands of students from many universities in Istanbul met in Maçka Park and then marched towards ?i?li.

Authorities in Istanbul banned protests and closed some roads "in order to maintain public order" and "prevent any provocative actions that may occur".

As students marched through the Nisantasi district they chanted "government, resign!" and waved flags and banners as they were watched by a large deployment of riot police.

Many students had their faces covered with scarves or masks, and acknowledged they feared being identified by the police

Turkey's main opposition party, the Republican People's Party (CHP), said that Tuesday's rally outside Istanbul's City Hall would be its last in a run of nightly gatherings - and that it is planning a rally in the city on Saturday.

"Are you ready for a big rally in a large square in Istanbul on Saturday?" Ozgur Ozel told crowds.

"To support Imamoglu, to object to his arrest, to object to the detention of each of our mayors. To demand transparent, open, live broadcast trials, to say that we have had enough and we want early elections."

Since last Wednesday, Turkey's interior minister said 1,418 protesters have been detained following the days of demonstrations that the government has deemed "illegal."

Posting on social media Ali Yerlikaya wrote: "While there are currently 979 suspects in custody, 478 people will be brought to court today.

"No concessions will be made to those who attempt to terrorise the streets, to attack our national and moral values, and to our police officers."

Elsewhere on Tuesday, seven journalists appeared in court including AFP news agency photographer Yasin Akgül who had been covering the demonstrations.

AFP chairman Fabrice Fries has written a letter addressed to the Turkish presidency urging Erdogan to "intervene" in Akgul's imprisonment which he described as "unacceptable".

"Yasin Akgül was not part of the protest," Fries said. "As a journalist, he was covering one of the many demonstrations that have been organized in the country since Wednesday 19 March.

"He has taken exactly 187 photographs since the start of the protests, each one a witness to his work as a journalist."

In Washington, Secretary of State Marco Rubio voiced "concerns" following a meeting with Turkish Foreign Minister Hakan Fidan, the US State Department said in a statement.

Imamoglu was one of more than 100 people detained last week as part of an investigation. Others arrested included politicians, journalists and businessmen.

His arrest does not prevent his candidacy or election as president, but he will not be able to run if he is convicted of any of the charges against him.

The opposition mayor is seen as one of the most formidable rivals of Erdogan, who has held office in Turkey for 22 years as both prime minister and president.

Erdogan's term in office is due to expire in 2028, and under the current rules, he cannot stand again – but he could call an early election or try to change the constitution to allow him to remain in power for longer.

Turkey's Ministry of Justice has criticised those connecting Erdogan to the arrests, and insisted on its judicial independence.