Russia's foreign minister, meanwhile, said that Damascus has consolidated its chemical weapons into one or two locations to protect them from a rebel onslaught.
Concerns over Syria's chemical arsenal have escalated as the regime of President Bashar Assad suffers losses on the battlefield. U.S. intelligence officials have said the regime may be readying chemical weapons and could be desperate enough to use them, while both Israel and the U.S. have also expressed concerns they could fall into militant hands if the regime crumbles.
Moscow's Foreign Minister Sergey Lavrov said Russia, which has military advisers training Syria's military, has kept close watch over Damascus's chemical arsenal. He said the Syrian government has moved them from many arsenals to just "one or two centers" to properly safeguard them.
Lavrov also told reporters on a flight from an EU summit late Friday that countries in the region had asked Russia to convey an offer of safe passage to Assad.
Syria refuses to confirm or deny if it has chemical weapons but Damascus is believed to have nerve agents as well as mustard gas. It also possesses Scud missiles capable of delivering them.
Meanwhile, the Britain-based Syrian Observatory for Human Rights reported that one rebel group has issued an ultimatum to the towns of Mahrada and Sqailbiyeh in the province of Hama.
A video released by rebels showed Rashid Abul-Fidaa, who identified himself as the Hama commander of the Ansar Brigade, calls on residents to "evict" regime forces or be attacked.
"Assad's gangs in the cities are shelling our villages with mortars and rockets destroying our homes, killing our children and displacing our people," said Abdul-Fidaa, who wore an Islamic headband and was surrounded by gunmen. "You should perform your duty by evicting Assad's gangs," he said. "Otherwise our warriors will storm the hideouts of the Assad gangs."
He accused regime forces of taking positions in the two towns in order to "incite sectarian strife" between Christians and the predominantly Sunni opposition. Assad belongs to the Alawite minority sect, an off-shoot of Shiite Islam.
Mahrada was the hometown of Ignatius Hazim, the former Patriarch of the Damascus-based Eastern Orthodox Church who passed away on Dec. 5 at the age of 92.
Christians, who make up about 10 percent of Syria's population, say they are particularly vulnerable to the violence sweeping the country of 22 million people. They are fearful that Syria will become another Iraq, with Christians caught in the crossfire between rival Islamic groups.
The conflict started 21 months ago as an uprising against Assad, whose family has ruled the country for four decades. It quickly morphed into a civil war, with rebels taking up arms to fight back against a bloody crackdown by the government. According to activists, more than 40,000 people have been killed since March 2011.
Clashes between troops and rebels in the central city of Homs, Syria's third largest, have already displaced tens of thousands of Christians, most of whom either fled to the relatively safe coastal areas or to neighboring Lebanon.
Rami Abdul-Rahman, who heads the Observatory, said some Christians and Alawites have also left Hama province in the past several days to escape violence. He said some of them found shelter in the coastal city of Tartus.
The push by rebels in Hama province came days after they opened a new front against regime forces attacking checkpoints and army posts in the central region.
The new Eastern Orthodox Patriarch John X. Yaziji, who replaced Hazim, told reporters in the capital Damascus Saturday that the church is "deeply-rooted in Syria." He added that Christians in Syria are not part of the conflict and will continue to coexist with people of the region urging rival Syrian factions to negotiate a settlement through dialogue.
"We are staying here and this is our land," he said.
Activists and state media reported violence in different parts of Syria on Saturday including in the capital Damascus and the northern city of Aleppo, Syria's largest.
In Damascus, the state-run news agency SANA said gunmen assassinated Saturday Haider al-Sammoudi who works as a cameraman for the government's TV station. Several journalists working for state media have been assassinated over the past months.
In another development, 11 rebel groups said they have formed a new coalition, the Syrian Islamic Front.
A statement issued by the new group, dated Dec. 21 and posted on a militant website Saturday, described the group as "a comprehensive Islamic front that adopts Islam as a religion, doctrine, approach and conduct."
Several rebel groups have declared their own coalitions in Syria, including an "Islamic state" in the embattled city of Aleppo.
The statement said the new group will work to avoid differences or disputes with the other Islamic groups.
Syrian authorities meanwhile handed over to Beirut three Lebanese citizens who were killed last month in a clash with Syrian troops shortly after they crossed the border. Syria has so far returned 10 bodies to the Lebanese authorities and says it has no more.
Associated Press writer Maamoun Youssef in Cairo and Alblert Aji in Damascus contributed to this report.