Tens of thousands of protesters took to the streets around Syria, after activists said troops had killed at least 45 civilians in a tank assault to occupy the centre of Hama.
From the capital, Damascus, to Deraa in the south and Deir ez-Zoor in the east - demonstrators began rallying after noon prayers on the first Friday of the fasting month of Ramadan - billed by activists as the day "God is with us".
Other protests were being held in Qamishli in the north and Homs in the centre, activists said, as President Bashar al-Assad sought to crush a five-month-old uprising against his rule, leaving the city of Hama under siege for the sixth day.
Armed men in plain clothes were randomly shooting people in the city's streets, forcing families to bury their loved ones in gardens at home for fear of venturing out to cemeteries, a Hama resident said on Thursday.
Phones, internet and electricity have been cut or severely hampered for days.
The resident, who spoke by phone on the condition of anonymity for fear of reprisals, told the AP news agency that people are being forced to ration food to get by during Ramadan.
"People are being slaughtered like sheep while walking in the street," the resident said.
"I saw with my own eyes one young boy on a motorcycle who was carrying vegetables being run over by a tank."
He said he left Hama briefly through side roads to smuggle in food supplies.
The resident said around 250 people have been killed since Sunday.
The claims could not be independently verified as Syria is not allowing journalists into the country to cover the uprising.
Hillary Clinton, the US secretary of state, has said that Washington believes Assad's government was responsible for more than 2,000 deaths in the crackdown, repeating that the US believes the president has "lost his legitimacy to govern the Syrian people".
"We are working around the clock to try to gather up as much international support for strong actions against the Syrian regime as possible," Clinton said.
"I come from the school that actions speak louder than words."
Hozan Ibrahim, of the Local Co-ordination Committees which tracks the crackdown on protesters, said up to 30 people may have been killed in Hama on Wednesday based on reports from fleeing residents. But neither of those numbers could be immediately verified.
Families have resorted to burying their loved ones in home gardens or roadside pits "because we fear that if we go to the cemetery, we will end up buried along with them", the resident said.
Rami Abdul-Rahman, who heads the London-based Syrian Observatory for Human Rights, said up to 1,000 families have fled Hama in the past two days, most of them to the village of Mashtal Hilu and al-Salamieh.
"The people of Hama want freedom, dignity, equality," Gaetan Vannay, a journalist with Radio Television Suisse, told Al Jazeera just three days after escaping from Hama.
"They want to get ride of Assad and his regime. But it will cost a lot of lives."
History of dissent
Hama, a city of 800,000 with a history of dissent, had fallen largely out of government control since June as residents turned on the government and blockaded the streets against encroaching tanks.
But Syrian security forces backed by tanks and snipers launched a ferocious military offensive that left corpses in streets on Sunday and sent residents fleeing for their lives, according to accounts.
In 1982, Assad's father, Hafez al-Assad, ordered the military to quell an uprising by Syrian members of the Muslim Brotherhood movement there, killing between 10,000 and 25,000 people, rights groups say.
Assad has sought to deal with the revolt against his family's 40-year-dynasty through deadly force, but has also acknowledged the need for reform.
He issued two legislative decrees on Thursday that will allow the formation of political parties alongside the Baath Party and enable newly formed parties to run for parliament and local councils.
Both draft bills were endorsed by cabinet last month, and were key demands of the opposition movement.
But opposition figures now dismiss the moves as manoeuvring tactics and insist they want regime change.
Even longstanding allies of Syria are becoming wary of uncritically backing Assad. Dmitry Medvedev, the Russian president, has called the situation in Syria "dramatic" and expressed "enormous concern" over the deadly violence in the country.
"Unfortunately, people die there in large numbers. This arouses enormous concern from us," he said in an interview given to Russian media in the southern resort Sochi on Thursday.
Assad needs to "carry out urgent reforms, come to terms with the opposition, restore peace and create a modern state", Medvedev said, as quoted by the Interfax news agency.
"If he cannot do this, a sad fate awaits him, and in the end we will have to take some decision. We are watching the way the situation develops. As it changes, some of our perspectives also change."
Medvedev's remarks followed a foreign ministry statement on Monday strongly criticising the Syrian government's crackdown on demonstrations in a sign of a possible shift in Russia's rigid position.
Russia supported the Security Council statement on Wednesday which condemned "the widespread violations of human rights and the use of force against civilians by the Syrian authorities".
However, it did not support stronger action rebuffing efforts by Western powers to agree on a resolution over fears that it might pave the way for another military intervention like the one against Muammar Gaddafi's rule in Libya.
Germany will ask the UN to send a special envoy to Syria to increase pressure on Damascus over its crackdown on civilian protesters, Foreign Minister Guido Westerwelle said on Thursday, a move aimed at adding weight to the Security Council's statement.
"Together with our partners, I will urge the UN to name a special envoy for Syria who will start work immediately, carrying the international community's clear message to Damascus and adding authority to the demands of the Security Council," Westerwelle said in a statement.
For its part, the US government warned on Thursday that Assad had placed Syria and the Middle East on a "dangerous path".
President Barack Obama's spokesman, Jay Carney, said Syria would be a "better place" without Assad and said people in Syria and around the world were making plans for a future without him.