Syrian Foreign Minister Walid Muallem will lead the government delegation at proposed peace talks in Geneva, Russia's top diplomat said Thursday, amid efforts to agree the format and timing of the conference.

"We are continuing to work with the (Syrian) government, which has already announced its readiness to take part in the conference and that the foreign minister will lead its delegation," Lavrov said in comments broadcast on state television.

Russia's counter-terrorism agency said Thursday that special forces have arrested a man for planning a terrorist attack on Moscow that the agency had foiled last month.

The National Anti-Terrorism Committee said in a statement that troops from the Federal Security Service, or FSB, arrested Yulai Davletbayev in suburban Moscow Thursday morning.

Senior diplomats failed on Wednesday to set a date for a widely anticipated international peace conference for Syria amid continued disagreement over the list of participants.

"It will not be possible to hold this conference in June," U.N. peace envoy to Syria Lakhdar Brahimi told reporters in Geneva, adding that the talks, which will be hosted by U.N. chief Ban Ki-moon, could happen "hopefully in July."

Russian Ambassador to Lebanon Alexander Zasypkin reiterated on Wednesday that his country supports stability and security in Lebanon, stressing that Moscow rejects any intervention in the country's local affairs.

“We back stability and security in Lebanon. The members of the U.N. Security Council all voiced their support to maintaining stability and security in Lebanon,” the ambassador said.

Thousands of commuters were evacuated from the Moscow metro on Wednesday after a high-voltage electric cable caught fire, filling station platforms with smoke at the height of the rush hour, emergency officials said.

The emergencies ministry said around 4,500 people were evacuated after the fire broke out in a tunnel between the Okhotny Ryad and Biblioteka Imeni Lenina (Lenin Library) stations close to the Kremlin at around 8:20 am (0420 GMT).

Shellfire near the Russian embassy in Damascus killed a civilian and wounded a member of the security forces on Tuesday, the Syrian Observatory for Human Rights reported.

"It was recorded that five shells hit the Al-Adwi area of Damascus," the Britain-based watchdog said.

Russian President Vladimir Putin said Tuesday Moscow had not yet delivered its sophisticated S-300 missiles to the Damascus regime despite hints from Syrian President Bashar Assad that such shipments had already been made.

"The contract was signed several years ago. It has not been realized yet," Putin said at a joint press conference with EU leaders. "We do not want to upset the balance in the region."

The European Union and Russia launched a full day of talks on Tuesday dominated by a far-ranging dispute over the Syria crisis and Brussels' decision to lift its arms embargo on President Bashar Assad's foes.

EU dignitaries said Russia's human rights record would also come under the microscope at meetings in the industrial Ural Mountains city of Yekaterinburg.

Russia cannot deliver advanced S-300 anti-aircraft missiles to the Syrian regime before 2014, Israel's defense minister asserted on Monday.

"We are following this matter with concern, but no deliveries have taken place. If they do take place, it will not be before next year," Moshe Yaalon told the parliamentary committee on foreign affairs and defense, in comments reported by army radio.

Syrian warplanes pounded the embattled town of Qusayr on Monday as a regime offensive backed by fighters from Hizbullah to retake the town from rebels entered its third week.

The Syrian Observatory for Human Rights reported a fierce overnight onslaught both on the strategic town near the border with Lebanon and slightly farther north in Dabaa.