Fresh unrest erupted in Ankara and Istanbul on Sunday, with police firing tear gas and water cannon amid continuing anti-government protests.
The unrest flared as supporters of Prime Minister Recep Tayyip Erdogan gathered for a huge show of strength in Istanbul.
About 1000 riot police from Turkish provinces have been flown to the city to try to curb the protests.
Police earlier broke up a protest camp in Taksim Square, the focal point of the unrest. The BBC reports a police cordon is now in place there, with bag searches and identity checks.
Police in Ankara also fired tear gas and water cannon to clear demonstrators in Kizilay Square on Sunday afternoon.
Two trade union groups have called a one-day nationwide strike for Monday.
The protests began on 28 May against a plan to redevelop Gezi Park in Istanbul.