Wounded British photographer Paul Conroy has been smuggled into Lebanon from the Syrian rebel city of Homs, which was today shelled by regime forces for a 25th day, his father and activists said.

News of Conroy's dramatic escape came as UN rights chief Navi Pillay called in Geneva for an immediate ceasefire to allow the delivery of humanitarian aid to violence-torn regions of Syria.

"We've just had word from Beirut," Conroy's father Les told British media.

The freelance photographer was working for Britain's Sunday Times newspaper when a makeshift media centre in Homs was shelled on February 22 by Syrian forces, killing veteran US reporter Marie Colvin and French photographer Remi Ochlik and wounding Conroy and French reporter Edith Bouvier.

France said it could not confirm reports that Bouvier had been evacuated from Syria but that it remained mobilised to do everything possible to secure her rescue.

"We do not at this stage have elements that permit us to confirm what some media have reported concerning Edith Bouvier," French foreign ministry spokesman Bernard Valero said.

"We are more mobilised than ever to do everything possible to allow for the evacuation of the wounded, of all foreign journalists and our wounded compatriot, from Homs," he added.

Conroy, 47, issued a video appeal for help last week, saying he was injured and being looked after by rebels of the Free Syrian Army.

A Lebanese activist said Conroy had been smuggled during the night from Homs to Lebanon through an illegal crossing.

"Conroy and people accompanying him entered the Wadi Khaled region through the Hnayder border village after midnight on motorbikes," said the activist in northern Lebanon who helps smuggle wounded people out of Syria.

The northern region of Wadi Khaled borders Syria and is close to the province of Homs, of which Homs city is the capital.

The Red Crescent and Red Cross had being trying for days to rescue the wounded pair and to retrieve the bodies of the dead but conditions were deemed too dangerous.

The latest attempt was made on Monday but it too failed, according to the head of the Arab-Syrian Red Crescent, Abdel Rahman Attar.

"Our team, composed of some 20 volunteers, extremely courageous with four ambulances and a hearse, entered Baba Amr and remained there for nearly three hours while representatives of the International Committee of the Red Cross (ICRC) waited outside," he said.

He said his team was told by an intermediary in Baba Amr that Bouvier refused to leave if the conditions she insisted on were not met.

Activists of the Syrian Revolution 2011 Facebook page said that Baba Amr was "bombarded for the 25th straight day by regime forces" on Tuesday.

"The shells are falling and the world watches," said an activist in a video showing columns of black smoke rising from bombed buildings.

The Syrian Observatory for Human Rights said at least five civilians had died on Tuesday in Baba Amr, while also reporting that five Syrian soldiers were killed in fighting against deserters in the restive southern province of Daraa.

The Britain-based monitoring group had reported more than 100 people killed Monday across Syria, including 11 members of the security forces, and 68 civilians in what it called a "massacre" in Homs province.

UN rights chief Pillay urged a ceasefire at the opening of an urgently-arranged debate on Syria at a Human Rights Council meeting in Geneva on Tuesday.

"There must be an immediate humanitarian ceasefire to end the fighting and bombardments," said Pillay, adding that since mid-February she had received reports of a rapidly deteriorating humanitarian situation and serious rights abuses, including a massive campaign of arrests by military and security forces.

The Syrian delegation attending the debate walked out of the meeting, criticising what it said was a "sterile discussion."

Western powers have said the violence called into question the veracity of a referendum held at the weekend, which Damascus said resulted in almost 90 percent of voters approving a new constitution.

The charter brought in by President Bashar al-Assad after 11 months of anti-regime protests won 89.4 percent of votes cast in Sunday's referendum, with a turnout of 57.4 percent, Interior Minister Mohammed al-Shaar announced.

In Washington, State Department spokeswoman Victoria Nuland asked how a democratic process such as Sunday's referendum could take place in the country while Syrian government guns and tanks were still firing.

"We dismiss it as absolutely cynical," Nuland told reporters.

"Even the referendum that they put forward is ridiculous in the sense that it requires that the state approve any of these patriotic opposition groups," Nuland said.

The draft text of the constitution that was overwhelmingly approved by voters ends the legal basis for the five-decade stranglehold on power of Assad's ruling Baath party but still leaves huge powers in his hands.

The Syrian opposition says the changes are cosmetic after nearly a year of repression by Assad's security forces that human rights groups say has left more than 7,600 people dead.

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