The Syrian government and the opposition exchanged accusations Monday over atrocities committed against civilians mainly in the central province of Homs over the past 24 hours, while the international community is still trying to figure out how to pull Syria out of the quagmire of simmering tension.

Syria's mainstream media refuted Monday allegations and amateur videos broadcasted by some Arab news TVs about atrocities allegedly committed by government troops, saying that the reports came as part of the "hysterical media campaign" against Syria ahead of the upcoming UN Security Council meeting.

The state-run SANA news agency quoted an unnamed media source as saying that armed terrorist groups kidnapped people in central Homs province, killed them and distorted their bodies, and later sent their pictures to media outlets to portray them as victims of military assaults on civilians.

"We have got used to such escalation by armed groups before the Security Council's sessions on Syria in order to press for aggressive stances toward the country," said the source.

The opposition Britain-based Syrian Observatory for Human Rights said at least 12 people were killed Sunday by pro- government gunmen. Another opposition group, the Local Coordination Committees, put the number of the alleged victims at 45, including children.

Meanwhile, the opposition at home held the government responsible for the bloodshed. Abdul-Aziz Khair, a member of the National Coordination Body, said the government is responsible for the bloodshed, calling for protection for the civilians in restive areas.

Another opponent Taib Tayzinin, a university professor, said that "I don't see any truth in the regime's account, and those armed men belong to the regime... It's a very dangerous matter and the regime must not be allowed to the do that."

"The one who is supposed to protect Homs is the regime and thus it's responsible for that," he said.

The Syrian government has accused some Arab and Western countries of providing weapons and financial support to the armed groups in Syria. It said in December 2011 that "armed terrorist groups" had killed more than 2,000 army and security personnel during the unrest.

The United Nations said recently that over 7,500 people died in Syria's violence.

On the international arena, the United States and Russia debated over the Syrian crisis in a ministerial-level meeting of the UN Security Council Monday. The two countries called for an end to the one-year-old domestic conflict but with different approaches.

U.S. Secretary of State Hillary Clinton said that the Security Council should not "stand silent when governments massacre their own people, threatening regional peace and security in the process. "

For his part, Russian Foreign Minister Sergei Lavrov said that "Hasty demands for regime change (are)... risky recipes of ' geopolitical engineering' which can only result in the spread of conflict."

"At this stage we should not talk about who was the first to start, but rather discuss realistic and feasible approaches which would allow (us) to achieve the ceasefire as a priority," he added.

After her meeting with Lavrov behind closed doors, Clinton said that "I pointed out that lack of unity will be dangerous, (and) bloody conflict will have regional implications."

Lavrov said that "There is no doubt whatsoever that the Syrian authorities bear a huge share of responsibility for the current situation." But he also pointed out that "no one can ignore the fact that for a long time now they've been fighting not unarmed men, but combat units, such as the so-called Free Syrian Army and extremist groups including al-Qaida which have lately committed a series of murderous terrorist acts."

Meanwhile, UN Secretary General Ban Ki-moon appealed to the Security Council "to unite strongly behind ending the violence and supporting (Kofi) Annan's mission to help Syria pull back from the brink of a deeper catastrophe."

During Monday's meeting, members of the UN Security Council overwhelmingly endorsed efforts by Annan, the joint UN and Arab League (AL) special envoy for Syria, to end the violence and bloodshed in Syria.

The former UN secretary general was appointed last month to that position by Ban and AL Secretary General Nabil al-Arabi.

Annan, who had two meetings with Syrian President Bashar al- Assad over the weekend, said he left a series of proposals with Assad on ending the violence.