The death toll in Syria's civil war has topped 45,000, a watchdog said Wednesday, as a new push by peace envoy Lakhdar Brahimi to bring the warring parties to the negotiating table appeared to have failed.

The grim statistics added gravity to a warning by the United Nations that Syrians are losing hope of any end to the bloodletting and that the humanitarian situation across the country is rapidly deteriorating.

"In all we have documented the deaths of 45,048 people," Rami Abdel Rahman, head of the Syrian Observatory for Human Rights told AFP, adding that more than 1,000 people were killed in the past week alone.

He said those killed included "31,544 civilians, 1,511 defectors, 11,217 soldiers and 776 unidentified bodies."

The Observatory, which relies on a network of medics and activists on the ground, said the actual number of people killed since an uprising against President Bashar al-Assad's regime erupted in March last year could be as high as 100,000, with both sides concealing many of their casualties.

The Britain-based watchdog reported that army shelling of a village in the north Syrian province of Kahtaniyeh on Wednesday killed at least 20 people, among them eight children and three women.

It also reported new clashes in the Yarmuk Palestinian camp in southern Damascus, the site of fierce fighting last week.

"The camp was relatively quiet until Tuesday night, but new clashes broke out that lasted through the early hours of the morning," said Abdel Rahman.

Violence first broke out in Yarmuk -- home to some 150,000 people -- when regime warplanes carried out an air strike on the camp on December 16, killing at least eight people.

For five days, battles in the camp pitted Syrian and Palestinian rebels opposed to Assad's regime against pro-Damascus Palestinian militia.

The army later surrounded the camp but allowed people who initially fled to return last Thursday.

Residents of the Palestinian refugee camp of Yarmuk in the Syrian capital Damascus return to their homes on December 20, 2012 after fighting had sent them fleeing. More than 45,000 people have been killed in Syria since the outbreak in March 2011 of an anti-regime revolt that became a bloody insurgency after a brutal crackdown on dissent, a watchdog said Wednesday.

Brahimi arrived in Syria on Sunday to push a new initiative aimed at ending the bloodshed and getting the regime and opposition to the negotiating table.

A UN security council diplomat however said the veteran Algerian diplomat had received no support from any of the warring parties.

"Assad appears to have stonewalled Brahimi again, the UN Security Council is not even close to showing the envoy the kind of support he needs and the rebels will not now compromise," the diplomat said on condition of anonymity.

Opposition activists also blasted Brahimi.

"Brahimi's arrival in Damascus to discuss a new political initiative to solve the crisis caused by the regime... has not put a stop... to massacres," the Local Coordination Committees, a grassroots network of anti-regime activists said on Tuesday.

The LCC rejects "any initiative that puts Syrians in a position where they are extorted and forced to choose between accepting unfair compromises, or the continuation of the regime's crimes against them."

A French daily has reported a supposed US-Russian initiative for a transition in Syria, causing rage among opponents who reject any compromise with the regime.

Le Figaro said a solution in the offing would involve keeping Assad in power until 2014 while preventing him from further renewing his mandate.

The United Nations said worse was to come inside Syria.

With four million people in need of aid inside Syria and well over 500,000 registered as refugees outside, "it's becoming more and more difficult just to do the very basic things to help people to survive," John Ging, a top UN relief official, said in New York on Tuesday.

"People are losing hope because they just see more violence on the horizon, they just see a deterioration."

Analysts, meanwhile, said only a few in Assad's regime now controlled power.

"Power has become increasingly concentrated in the hands of just a few people in Assad's clan, which has grown autistic and seems to have chosen to just keep going," Paris-based expert Karim Bitar told AFP.

"Bashar, who runs the show, only listens to people who owe him, for the most part, for their rise," said another analyst on condition of anonymity.