ANKARA (AFP) - Turkey's artists, journalists and authors including Nobel laureate Orhan Pamuk on Saturday placed a full-page ad in several newspapers, calling on the government to end divisive language and stop polarising the country.

The move comes after recent protests that turned violent and which have threatened to shake the Islamic-rooted Justice and Development Party (AKP) government to its core.

The anti-government demonstrations prompted Prime Minister Recep Tayyip Erdogan who faced the greatest public challenge of his decade-plus rule to lash out at demonstrators including artists as being members of "marginal groups".

"We are concerned," the artists wrote in the ad. "The 'you vs. us' rhetoric is sharpening polarisation in society," they warned, calling for an end to pressure.

Observers say Mr Erdogan inflamed tensions by dismissing the protesters, mostly young, middle-class and well-educated as "looters" or naive youngsters who were being manipulated by "terrorists".

He also deepened divisions by holding rallies to fire up tens of thousands of AKP loyalists, telling them he would stand firm against the protesters and that he took orders only "from God".

Mr Erdogan has won three succesive elections, gaining in popularity each time.

At the last elections in 2011, his AKP took nearly half the vote and Mr Erdogan routinely refers to his supporters as "the 50 per cent." In return, many protesters turned the table on the catchphrase, referring to themselves as "the other 50 per cent."

On Monday, the BBC expressed concerns about what it called a campaign launched by Turkish authorities to "intimidate its journalists" as government officials also lashed out at international media for their coverage of the unrest.

Ankara Mayor Melih Gokcek has started a campaign via Twitter against BBC Turkish correspondent Selin Girit, accusing the journalist of acting as a spy for Britain.

The crisis began on May 31 when police responded brutally to a small campaign to save an Istanbul park from being razed in a redevelopment project, sparking fury and spiralling into mass demos against Mr Erdogan and his ruling AKP.

The protests were met with a heavy police response, leaving four people dead and nearly 8,000 injured across the country.

Mr Erdogan's government has been widely criticised for its handling of the crisis, with the United States and other Western allies condemning the use of excessive police force against protesters.

The Turkish leader however has claimed victory after retaking Gezi Park, depriving demonstrators of their main rallying site.

A recent poll found that the AKP would still come first if elections were held today, but only with 35.3 per cent of the vote.