Syrian forces crackdown kills 20 protestors

Video footage has been placed online by activists, claiming to show the clampdown on demonstrations that left 20 people dead.

According to reports, Syrian security forces opened fire as thousands of anti-government protesters took to the streets after Friday prayers.

In a weekly ritual of defiance amid demands for President Bashar al Assad to be ousted, a number of people - including a young child - were reported to have been shot dead.

An activists' group said it had the names of 14 civilians killed in the city of Homs, the town of Kiswa south of Damascus and in the residential district of Barzeh in the capital.

Another protester was shot dead in the town of Qusair, the group said.

Syrian state TV blamed the killings in Barzeh on armed men who authorities say are behind the violence in the three-month uprising.

It added that members of the security forces were wounded.

Meanwhile, America has warned the crisis in Syria is in danger of escalating as pro-Assad troops were reportedly massing near the Turkish border where thousands of refugees have fled the violence.

US Secretary of State Hillary Clinton said the reported move by Syria to surround and target the border town of Khirbat al Joz marks a worrying new phase of Syria's attempt to quash anti-regime protests.

"If true, that aggressive action will only exacerbate the already unstable refugee situation in Syria," Clinton said.

"Unless the Syrian forces immediately end their attacks and their provocations that are not only now affecting their own citizens but (raising) the potential of border clashes, then we're going to see an escalation of conflict in the area."

The European Union said it had expanded its sanctions list, targeting seven more people and four companies.

It brings to 34 the number faced with an asset freeze and travel ban, including President Assad.

The EU also has an embargo on the sales of arms and equipments that can be used to suppress demonstrations.

Most foreign journalists are banned from the country and local media is restricted.

A Turkish Red Crescent official said about 600 Syrians had crossed the border on Thursday morning.

Syrian troops stormed the village of Managh, nine miles south of the border and just north of the commercial hub of Aleppo, according to residents.

"I was contacted by relatives from Managh. Armoured personnel carriers are firing their machine guns randomly and people are fleeing the village in all directions," an Aleppo resident said.

The Turkish Foreign Ministry said the border remains open and refugees continued to arrive.

Human rights groups say more than 1,300 civilians have been killed across Syria since mid-March.