There have been fresh anti-government protests in Turkey, with some of the most violent clashes since the trouble started three days ago.
Protesters fought with police overnight Sunday, using paving stones to build barricades, the BBC reported.
More than 1,700 people were reported to have been arrested in separate 235 demonstrations.
Police used tear gas and water cannon to repel the protesters.
There were some of the most violent scenes so far
The unrest was triggered by plans to develop a city park but have since widened.
Hundreds of people were injured, and roads around Prime Minister Tayyip Erdogan's office in Istanbul were sealed off, Reuters reported.
Erdogan blamed the main secular opposition party for inciting the crowds, whom he called "a few looters", and said the protests were aimed at depriving his ruling AK Party of votes as elections begin next year.
The Foreign Office has issued advice to British tourists to avoid the demonstrations.