Five EU nations have summoned Syrian ambassadors to condemn Damascus' recent violent crackdown on anti-government protesters, France has said.
Paris said the diplomatic action had been carried out jointly by France, Britain, Germany, Italy and Spain.
Earlier, UN chief Ban Ki-moon condemned Syria for using tanks and live ammunition against the demonstrators.
There are reports of further shooting in the southern city of Deraa, where the rallies first erupted last month.
More tanks are said to be headed for city - where army troops attacked protesters on Monday.
'Snipers' in Deraa
More than 450 people across Syria have allegedly been killed since the pro-democracy protests began nearly six weeks ago.
The government of President Bashar al-Assad disputes the Western view that the demonstrations have been non-violent.
In a statement carried by the official news agency, it said it had sent troops to several cities on the request of citizens who were worried about "armed extremists". Opposition leaders say the protests are peaceful.
Senior French diplomat Herve Ladsous met Syrian ambassador Lamia Chakkour on Wednesday, the French foreign ministry said.
It said that Paris expressed "firm condemnation of the escalation of the repression by Syrian authorities against the population".
The communication was "part of a co-ordinated move with Britain, Germany, Spain and Italy".
EU envoys are also due to meet in Brussels on Friday to discuss imposing sanctions on Syria.
Meanwhile, in Deraa, sources reported sporadic shooting and explosions on Wednesday.
Footage posted on the internet appeared to show Syrian tanks heading towards the city to reinforce troops who moved into it two days ago.
Amnesty International quoted eyewitnesses as saying army snipers were shooting at wounded residents lying in the streets and that other people were trying to save them.
But with communications apparently cut off from Deraa, it is hard to be sure what is happening there, the BBC's Jim Muir in neighbouring Lebanon says.
Elite army units were also said to have moved into Douma, a suburb of Damascus, our correspondent adds.
He adds that there are also reports of widespread arrests of opposition figures around the country.
Despite the crackdown, protest organisers have called for sit-ins on Thursday to commemorate those who have been killed. Friday - the traditional day of protests - had been designated as a "day of rage".
The death toll has now risen to 453 since the start of the unrest, the Syrian Observatory for Human Rights says.
'Refusal to fire'
On Wednesday, a human rights activist said he had documented the case of a soldier being shot by the army for refusing to fire on protesters in Baniyas.
The army blamed radical Islamists for his death, but mourners at the soldier's funeral "openly accused the security forces of shooting that soldier", Wissam Tarif, director of the Syrian human rights organisation Insan, told the BBC.
The UN Security Council discussed Syria at a meeting in New York but did not agree on a statement condemning the Syrian government for the violence.
The text - proposed by the UK, France, Germany and Portugal - condemned the violence against civilians and backed Mr Ban's call for a "transparent" independent investigation into deaths in the protests.
The Syrian envoy to the UN, Bashar Jaafari, said Damascus was capable of carrying out its own inquiry and had "nothing to hide".
Diplomats at the UN said Russia, China and Lebanon were against the statement. Council veto-holders China and Russia have been especially cautious about Syria as they are unhappy about the intervention in Libya.
Speaking to the council, Russia's UN ambassador said the unrest in Syria "does not represent a threat to international peace and security".
Instead, "a real threat to regional security could come from outside interference," Alexander Pankin said.
"Such approaches lead to a never ending circle of violence," he added.
source : bbc.co.uk
