A Turkish court on Monday sentenced a former army chief and other top brass to life in prison in a high-profile trial of 275 people accused of plotting to overthrow the Islamic-rooted government.

Police fired tear gas at protesters outside the court in a town near Istanbul as the verdicts were being delivered in the highly-divisive case.

Syria's opposition National Coalition will meet in Istanbul on August 3 and 4 for talks on forming a provisional government, opposition sources said Thursday.

In Paris this week for meetings with French officials, Coalition vice president Suheir Atassi said opposition talks would be held on August 3 and 4 in order to "strengthen" the group's position.

Turkish riot police on Monday fired rubber bullets, tear gas and water cannon to block demonstrators from entering a small Istanbul park, the birthplace of deadly unrest that engulfed the country last month.

Police moved after Turkish authorities reopened Gezi Park to public use earlier in the day.

Turkish riot police fired tear gas and water cannon early on Wednesday to disperse some 2,000 protesters in the capital Ankara, making 16 arrests.

Protesters had gathered overnight in the Dikmen district of the capital and attempted to erect barricades to block traffic on a main artery.

Turkish authorities arrested 23 more people on Saturday over their alleged role in this month's anti-government protests, accusing them of acting on behalf of a far-left "terrorist" group, a news report said.

A court in the capital accused them of helping to organize the protests and engaging in violence in the name of the Communist Marxist-Leninist Party (MLKP), CNN-Turk said on its website.

Riot police on Wednesday clashed briefly with groups of anti-government protesters in two Turkish cities, but there was no fresh unrest in Istanbul where demonstrators switched to silent protests after a heavy crackdown.

A day after Prime Minister Recep Tayyip Erdogan claimed victory over the mass demos that have defied his authority for nearly three weeks, several dozen protesters held a quiet vigil on Istanbul's Taksim Square, standing still and silent in the midday heat.

German Chancellor Angela Merkel said Monday that she was shocked by Turkey's violent crackdown on protests in major cities, saying it "was much too harsh".

"There were horrible images in which one could see that the approach was much too harsh in my view," Merkel told commercial broadcaster RTL in reaction to news coverage of riot police breaking up demonstrations in Istanbul and the capital Ankara.

Representatives from countries that support the Syrian opposition met Friday in Istanbul with rebel military chief General Selim Idriss, to discuss the possible delivery of weapons, a Syrian opposition spokesman said.

"Over the next 24 to 48 hours, there are going to be several meetings between the Syrian Military Council (SMC) and different countries to understand the needs of the SMC and to begin to really satisfy those needs," said Khaled Saleh, a spokesman for the opposition Syrian National Council.

Turkey's Prime Minister Recep Tayyip Erdogan on Friday agreed to halt plans to redevelop an Istanbul park at the center of two weeks of mass anti-government unrest, in a move protesters welcomed as "positive."

It marked the first easing of tensions in the standoff, which has presented the Islamist-rooted government with the biggest challenge of its decade-long rule and earned it criticism from the West.

Turkish protesters said Thursday they would remain in Istanbul's Gezi Park despite a "last warning" by Prime Minister Recep Tayyip Erdogan to evacuate the green patch at the center of deadly anti-government unrest.

"We will stay in Gezi Park with all our demands and sleeping bags," Taksim Solidarity, the core group behind the campaign to save the park, said in a statement, rejecting the government's proposal to hold a referendum on the site's controversial redevelopment.