The UN security council is holding an emergency meeting on Sunday evening to discuss the massacre in Houla, Syria according to Sky News.
Gruesome video footage emerged earlier on Sunday showing rows of dead Syrian children lying in a mosque with gaping head wounds.
It is the the worst bloodshed since the start of the U.N peace plan, the violence sparked by anti-government forces retaliating to shelling by Assad's forces, according to The Guardian.
The UN meeting was set up after Russia rejected the statement that was issued jointly by the UK and France condemning the killings, according to BBC News.
Russia and China have been the principal opponents of stronger action against the Syrian regime by the UN.
The Syrian government flatly denied claims that its forces were responsible for the slaughter, blaming "terrorists".
Foreign Secretary William Hague has called for a "strong" international response over the "stomach-churning" massacre of civilians, including dozens of children.
Mr Hague is travelling to Moscow on Monday to discuss the matter with Russia's foreign minister.
Speaking on Sunday, Mr Hague said he was "absolutely sickened" by the recent deaths in Syria.
"It isn't in the interests of Russia, it's not in anyone's interests, for Syria to descend into an even bloodier situation and into a full-scale civil war and that's now the danger," he added.
"We are absolutely sickened in the British government and across the international community by what we've seen over the last few days, in particular about the deaths of more than 100 unarmed men, women and children."
He said they were "more statistics" to add to a "huge total" that demonstrate the "brutality and murderous nature of the regime", adding that the deaths "illuminate the type of tyranny that the people in Syria have been experiencing".
He said: "It is a familiar tactic of the Assad regime to blame others for what's happening in their country to try to get out of responsibility for the scale of the destruction.
The Foreign Office has said it will issue a diplomatic reprimand to the Syrian charge d'affaires on Monday over one of bloodiest episodes in the country's 14-month-old uprising.
The diplomat has been summoned to the Foreign Office amid international outrage over the attack on Houla, in central Syria, resulting in the deaths of more than 90 people, including 32 children under the age of 10, according to United Nations observers.
Local activist Abu Yazan told the paper that the shelling killed 12 people, with 106 killed by pro-regime thugs called "shabiha".
He said: "They killed entire families, from parents on down to children, but they focused on the children."
Foreign ministry spokesman Jihad Makdissi said that Syria is being subjected to a "tsunami of lies" and claimed that anti-government gunmen carried out the attack.
"We categorically deny the responsibility of government forces for the massacre," Mr Makdissi said.
Foreign Office minister Alistair Burt said the council would need "all the options on the table" at the meeting.
Mr Burt said the Foreign Secretary would be meeting the Russian foreign minister in Moscow tomorrow. Russia and China have been the principle opponents of stronger action against the Syrian regime by the UN.
"There should be an urgent meeting of the Security Council and they will have to have all the options on the table that they need in order to show that the international community cannot be thwarted," Mr Burt told Sky News.
The Syrian charge d'affairs will tomorrow meet the Foreign Office's political director, Sir Geoffrey Adams, who will inform him in person of Britain's condemnation of the regime's actions.
In a statement yesterday, Mr Hague said: "Our urgent priority is to establish a full account of this appalling crime and to move swiftly to ensure that those responsible are identified and held to account.
"We are consulting urgently with our allies on a strong international response, including at the UN Security Council, the EU and UN human rights bodies."
The massacre comes after a Syrian general with links to President Bashar Assad declared his determination to come to Britain for the London Olympics.
General Mofwaq Joumaa, president of the Syrian National Olympic Committee, said that he would complain to the International Olympic Committee if his visa was denied.
Visas are still being sought for all of the 11 athletes and 20 officials - including coaches - wanting to attend the games on behalf of Syria, whose regime has been condemned by Britain for its brutal crackdown on opponents.
It is thought that the athletes may receive visas because those of Olympic standard are not required to serve in the armed forces, but there is a question mark against General Joumaa and other officials.
General Joumaa said: "If anyone was blocked because of their military background, that would be unfair. Anyone who has a military background in Syria, they are an ordinary citizen of this country.
"You have seen how much Syria enjoys security and safety. We are a peaceful country. The Syrian people have love in their hearts for the British people."
Mr Clegg said today that no figures associated with atrocities would be allowed into Britain, under new rules preventing entry for people who are not "conducive to the public good".
Deputy Prime Minister Nick Clegg told BBC1's Andrew Marr Show: "The scenes of savagery that we have seen on our television screens are revolting, stomach-churning."
However, he would not give assurances on specific individuals.
"As far as we are concerned we have recently said very clearly if you have abused human rights and that is shown to be the case you can't come into this country," he said.
Asked whether anybody connected to the atrocities in Syria would be blocked from coming for the Olympics, he said: "Of course, what I can't tell you is exactly who those names are."
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