Istanbul - Turkish police fired tear gas at protesters in Ankara on Sunday while thousands of people occupied Istanbul's main Taksim Square on the third day of mass demonstrations against Turkey's Islamist-rooted government.
Interior Minister Muammer Guler said more than 1 700 people had been arrested in the unrest that has spread to 67 cities nationwide, though most have since been released.
In Istanbul, a sea of protesters from across Turkey's political spectrum flooded Taksim a day after police pulled out of the area, waving flags and chanting "Government, Resign!" and "Istanbul is ours, Taksim is ours!"
From a nearby rooftop, a banner with the words: "Do not surrender" was unfurled.
Taksim has been at the heart of a wave of protests that have spread across the country in the biggest public outcry against Prime Minister Recep Tayyip Erdogan's government since it took power in 2002.
Rights groups have complained about what they said were a "disgraceful" heavy-handed response by police to the demonstrations while Turkey's Western allies appealed for restraint.
The unrest began as a local outcry against plans to redevelop Gezi Park near Taksim, but after a heavy-handed police response quickly snowballed into broader protests against what critics say is the government's increasingly conservative and authoritarian agenda.
After two days of violence, the situation appeared to have calmed in Istanbul on Sunday after police pulled out of Taksim and officials adopted a more conciliatory tone.
But in Ankara police fired tear gas and used water cannon to disperse about 1 000 protesters who were attempting to march on the prime minister's high-security office, images that were shown live on a television network.
Amnesty International said some protesters had been left blinded by the massive quantities of tear gas and pepper spray used by police.
Amnesty's Europe director John Dalhuisen said police excesses had become routine in Turkey "but the excessively heavy-handed response to the entirely peaceful protests in Taksim has been truly disgraceful."
Human Rights Watch said the number of injured was higher than official figures suggested and that one protester had lost an eye.
Turkey's Nato allies Britain, France and the United States have all urged the Erdogan government to exercise restraint.