The head of the Russian parliament's foreign affairs committee is to visit Syria next week for talks with its leadership amid concern over the growing bloodshed, he announced on Thursday.

Alexei Pushkov, the head of the international affairs committee of the State Duma lower house, told the Interfax news agency that his visit was aimed at reporting back to parliament about the situation inside the country.

U.N. chief Ban Ki-moon called on Thursday for all sides to end the deadly violence in Syria and urged the international community to find a common response to the 11-month-old crisis.

"What is important at this time is that first the Syrian authorities must stop killing their own people," Ban told journalists on a visit to Vienna.

Security forces on Thursday arrested blogger Razan Ghazzawi, icon of the 11-month uprising in Syria, along with rights activist Mazen Darwish and 12 others, opposition figures said.

Human rights lawyer Anwar Bunni said Ghazzawi was arrested in an early afternoon raid on the Syrian Center for Media and Freedom of Expression, which is located in central Damascus and is headed by Darwish.

Syrian armor moved on the main hubs of an 11-month uprising on Thursday killing at least 22 people, monitors said, a day after President Bashar Assad set a vote for a new constitution.

Opposition groups rejected the newly proposed constitution and urged voters to boycott a referendum set for this month, and to step up efforts to oust Assad.

Syrian Ambassador to Lebanon Ali Abdul Karim Ali praised on Thursday Lebanon’s stance at the Arab League, which decided to disassociate itself from the turmoil in Syria.

Ali held a meeting with Foreign Minister Adnan Mansour, who informed him about the Arab League’s meetings on development in Syria.

China said Thursday it is sending an envoy to Syria to push for a "peaceful" resolution of the conflict there, after drawing condemnation for vetoing a resolution condemning a crackdown on protesters.

Vice Foreign Minister Zhai Jun will visit Syria from February 17 to 18, foreign ministry spokesman Liu Weimin told a regular briefing.

A Syrian opposition group on Thursday rejected a newly proposed constitution, urging voters to boycott a referendum set for later this month and to step up efforts to oust President Bashar Assad.

"The Local Coordination Committees calls upon our people to reject and boycott the alleged referendum to confirm the lack of public support for this criminal regime," the opposition group said in a statement.

Seven Iranian engineers kidnapped near Syria's embattled city of Homs in late December have not been released as previously reported, and remain captives, the Iranian foreign ministry said on Thursday.

"We hope to witness the freedom of the Iranian engineers and the rest of pilgrims soon," ministry spokesman Ramin Mehmanparast was quoted as saying by the Fars news agency.

Switzerland Wednesday said it was closing its embassy in Damascus and urged its nationals to leave Syria "as quickly as possible".

The embassy closure, which follows that by the United States, was announced by Swiss Foreign Minister Didier Burkhalter and comes against a background of increasing violence inSyria where the regime is seeking to crush a nearly year-long rebellion.

Turkey urged the United Nations on Wednesday to appeal to the Syrian leadership to allow a humanitarian operation to help Syrians suffering from the months-long bloodshed.

Speaking to reporters, Foreign Minister Ahmet Davutoglu said the U.N. should step in not only on political matters "but also on humanitarian issues," vowing that Turkey would keep the Syrian crisis "on the U.N. agenda."