The protest movement in Syria has spread both in scope and intensity, despite attempts by President Bashar al-Assad to stem the tide by speeding up reforms, according to experts.

Geographically, pro-reform demonstrations have spread across most of the country while the mood of the protesters has visibly hardened, with increasing calls for the regime to fall.

A repressive response from the government which has seen troops firing live rounds at protesters, killing at least 200, according to Amnesty International, has fed the anger.

And government promises to suppress an "armed revolt" it says is undermining security will only add fuel to the fire.

The interior ministry issued the warning and then the security forces on Tuesday broke up a sit-in by thousands of protesters at a main square in the central city of Homs.

It accused armed Salafist groups of killing soldiers, policemen and civilians, and of attacking public and private property, and warned that "their terrorist activities will not be tolerated."

Bassma Kodmani, a Syrian researcher at the Arab Reform Institute which operates out of Paris and Beirut, said the harsh response by the security forces was adding provocation.

"Security forces, who are there to assure the stability of the regime, are the main reason for the mood of destabilisation, as their response has provoked the people," Kodmani said.

What began with a relatively small protest by a few dozen people, buoyed by the success of the uprisings in Egypt and Tunisia, has now mushroomed into a movement which embraces tens of thousands of people.

The main centres of unrest are in the agricultural province of Daraa in the south, the major towns of Latakia, Banias and Homs, as well as the Damascus suburbs, and has now spread further to the majority Kurdish regions in the north and for the first time to the Druze stronghold of Suwayda. Only Damascus and Aleppo have so far been spared.

Abdel Karim Rihaoui, president of the Syrian Human Rights League, said: "The protests have spread due to the growing anger at the use of force against protesters and it will only get worse if they carry on firing on the demonstrators and the security operation continues.

"The situation calls for rapid and serious measures to calm the mood in the street and rebuild the people's confidence, particularly by authorising peaceful demonstrations without the security forces intervening, freeing political prisoners and, of course, lifting the state of emergency ... as President Assad has promised," he added.

Burhan Ghaliun, director of the Centre for Arab and Contemporary Oriental Studies and a political sociology professor at the Sorbonne in Paris, said: "The regime is increasingly losing its room for manoeuvre as there is no clear agreement on precise policy.

"President Assad promises one thing and the security forces continue firing on protesters and that raises the danger of a tidal wave of demonstrations," Ghaliun said.

"Now, the slogans have completely changed, they are no longer calling for reform but they are calling for Bashar's head and that of the regime. We are in a spiral of radicalisation."

At the outset, the slogans were all about calls for reform and the liberalisation of a regime which has been in power for half-a-century, but now the order of the day is the fall of the regime itself.

On the other hand, analysts are divided on the role of political militants in the protest movement.

"In a society so dominated by the security services, it takes fairly committed and politicised activists to get things moving, people like the (Islamist) Muslim Brotherhood, communists and others. They could form the backbone of the movement," Kodmani said.

"I don't believe that it is only the young who are joining together on Facebook," she added. "There is a bit of that, for sure, but in Syria there are strong political allegiances."

But Ghaliun is more circumspect. "Political parties, including the Muslim Brotherhood, really don't have much influence at the heart of these movements.

"There are separate groups which are now starting to form a coordinated network in each town. There are the young who communicate via social networks and their ideas evolve progressively. At first, they only wanted to emancipate the system of oppression but now they weant to overthrow the regime."