Syrian activists say pro-government militia and security forces have killed at least 78 people, including women and children, in the central province of Hama. They say some of those killed in the villages of al-Kubeir and Maazarif Wednesday were stabbed to death and at least 12 bodies were burned.
The Britain-based Syrian Observatory for Human Rights said militiamen armed with guns and knives carried out the attack after regular troops had shelled the area.
The Observatory described a similar pattern of events as recounted from the May 25 Houla massacre in which 108 Syrian civilians were murdered, nearly half of them children. That incident has provoked international outrage.
Activists called for an immediate investigation. There was no comment from the Syrian government, and events on the ground are difficult to verify as Syria tightly restricts access to international media.
Meanwhile, senior U.S. officials are warning Syria and its backers that tougher international action against President Bashar al-Assad's government could follow unless Damascus demonstrates "meaningful compliance" with U.N efforts to end the violence.
U.S. Treasury Secretary Timothy Geithner said Wednesday the administration and its allies could soon tighten sanctions against the Syrian government and its leaders. He spoke to representatives from 55 countries gathered in Washington to discuss increasing pressure on Assad and his top officials.
"Strong sanctions, effectively implemented, aggressively enforced, can help deprive the Syrian regime of the resources it needs to sustain itself and to continue its repression of the Syrian people. Strong sanctions make clear to the Syrian business community and other supporters of the regime, their future is bleak so long as the Assad regime remains in power," he said.
Geithner said the U.S. would ask, if necessary, to invoke "Chapter 7" of the United Nations charter - a measure that could authorize the use of force. "We, the United States, hope that all responsible nations will soon join in taking appropriate economic actions against the Syrian regime, including, if necessary, Chapter 7 action in the U.N. Security Council as called for by the Arab League last weekend," he said.
U.S. Secretary of State Hillary Clinton echoed Geithner's call to choke the Syrian government's "economic lifelines" as she headed into a strategy session in Istanbul with key regional powers to discuss how to halt the violence in Syria and remove Assad from power.
Clinton said Wednesday "sanctions are specifically pointed at members of the regime and its war machine - they do not target the Syrian people and do not apply to supplies of critical goods." She said President Assad leaving power is not necessarily a condition for starting a political transition, but that must be its outcome.
Also Wednesday, U.N. diplomats said international envoy Kofi Annan will present the Security Council with a new proposal later this week to rescue his failing peace plan for Syria, where 15 months of violence have brought the country to the brink of civil war.
They said Annan's new plan would establish a "contact group" for Syria that would include the five permanent members of the Council and key regional players with influence on Damascus or the opposition, such as Saudi Arabia, Qatar, Turkey and Iran. The group would attempt to map out a "political transition" leading to Assad's departure and the holding of free elections.
An unnamed envoy leaked further details of Annan's proposal to Washington Post columnist David Ignatius, who wrote that if the contact group agreed on a transition deal for Syria, it would mean "Assad would presumably depart for Russia, which is said to have offered him exile." According to Ignatius, Iran is also said to have offered exile to Assad and his family.
In China, Russian Foreign Minister Sergei Lavrov seemed to follow up on the contact group idea, saying nations exerting influence over Syrian opposition groups should join an international gathering to rescue Annan's faltering cease-fire deal. Russia is a longtime ally of the Assad government and has blamed his opponents for much of Syria's violence. China and Russia issued a statement Wednesday saying they are "decisively" against military intervention in Syria and regime change.
Secretary Clinton reacted cooly to Lavrov's proposal for a meeting on Syria that would include Iran, saying it is "a little hard to imagine inviting a country that is stage-managing the Assad regime's assault on its people."
The State Department has said Iran's paramilitary Quds Force is training Syrian militia, like those who Washington believes responsible for last month's killing of civilians in Houla. Clinton meets with Kofi Annan on Friday.
As Western pressure continues, Assad appointed a loyalist Baath party member as the country's new prime minister Wednesday, the latest step of what the president has called a political reform process. State media said the prime minister-designate, Riad Farid Hijab, will form Syria's next government.
Snowiss reported from Washington and Stearns from Istanbul.