The leader of Germany's opposition voiced support on Friday for Turkey's full membership of the EU, describing it as a "win-win" for Ankara and Europe.

Turkey's efforts to join the 27-member bloc have stalled in recent years, largely due to its long-running dispute with Cyprus and fierce opposition from other EU states.

Turkey's Prime Minister Recep Tayyip Erdogan on Friday came under withering criticism from Israel, Washington and the United Nations for comments branding Zionism a "crime against humanity."

The storm surrounding the comments is likely to dominate Friday's visit to Ankara by the new U.S. Secretary of State John Kerry, who is due to hold talks there on the Syrian crisis.

Two more retired Turkish generals were jailed overnight in connection with a probe into a bloodless coup in 1997 that led to the removal of an Islamist-led government, the Anatolia news agency reported Thursday.

General Yucel Ozsir and former land forces commander General Erdal Ceylanoglu were among four ex-generals summoned to testify before prosecutors at an Ankara court on Wednesday, on the eve of the coup's 16-year anniversary.

The lack of clear leader among Syria's opposition is no reason to maintain support for the "cruel" regime of President Bashar Assad, Turkey's prime minister said Wednesday.

"The international community thus far unfortunately has not taken the kind of position it was expected to take," Recep Tayyip Erdogan said at a U.N. event in Vienna.

Four retired generals and a serving military officer testified in an Ankara court on Wednesday as part of an ongoing probe into the forced resignation of an Islamic-leaning government in 1997.

Aslan Guner, former war academies commander, and Erdal Ceylanoglu, former land forces commander, were among the four generals giving evidence to prosecutors on the eve of the coup's 16-year anniversary, state-run Anatolia news agency reported.

Hundreds of Turks staged a demonstration in Istanbul on Sunday in protest at the resumption of peace talks with Kurd rebels, saying they sullied the memory of soldiers killed in the near three-decade conflict.

"We want respect for Turks," "We want respect for the martyrs," the demonstrators chanted.

Turkish Prime Minister Recep Tayyip Erdogan said on Sunday that his country will "not remain silent" over Syrian President Bashar Assad's "crimes" against his own people.

"Every day a large number of innocent children and women fall dead in Syria," Erdogan said in a speech at the Government Communication Forum in the United Arab Emirates.

German Chancellor Angela Merkel on Saturday said she is in favor of opening up a "new chapter" in talks related to Turkey's bid to join the European Union, saying that even though she remains skeptical, discussions need to move forward.

"We conduct negotiations without the result being fixed in advance. These negotiations have stalled a little recently and I am in favor of opening a new chapter in these talks so we can advance," Merkel said in her weekly video message, but added "a long path of negotiations lies ahead of us".

Just like the centuries-old coffee tradition, the nargileh, or water pipe, is a mainstay of Turkish culture but authorities are clamping down on this ancient social ritual that health experts say is as harmful to health as smoking regular cigarettes.

Fans of the water pipe, also known as a hookah or shisha, can no longer get their fix in cafes, bars, and restaurants after a law banning smoking from closed public spaces came into force in January.

Turkey voiced hope that a presidential runoff in Cyprus Sunday would yield a "serious counterpart" for Ankara and pave the way for a peace deal between the island's Greek government in the south and its northern occupiers.

"I believe Christofias was a big joke," European Union Affairs Minister Egemen Bagis said in an interview to Agence France Presse this week, referring to President Demetris Christofias whose term runs out at the end of this month.