Air blitz death toll in Syria's Aleppo passes 400

Damascus: The death toll from a 10-day Syrian regime air offensive on Aleppo rebels passed 400 on Wednesday, as Pope Francis called on Christmas Day for aid access to the war-torn country.

But even as the European Union and Arab League condemned the aerial campaign in Syria's second city, a Russian company signed a major oil and gas exploration deal with the Damascus government.

Aleppo has been divided into regime and rebel-held enclaves since the opposition launched a massive offensive on the northern city in July last year.

The air force has been bombarding the rebel-held areas using TNT-packed barrels since December 15, in an offensive the Syrian Observatory for Human Rights said has left 410 people dead, including 117 children, as of Tuesday night.

Also among those killed were 34 women, 30 rebel fighters and nine jihadists.

The Observatory, a Britain-based group that uses a network of activists and witnesses on the ground to track the conflict, said the air force pressed the assault into an 11th day on Wednesday, with raids on the opposition-held eastern districts of Sakhur and Jabal Badro.

Human Rigths Watch has labelled as "unlawful" the relentless aerial campaign by President Bashar al-Assad's regime, especially the use of the massively destructive barrel bombs in civilian areas.

The United States has also condemned the aerial assault, and on Wednesday the Arab League and the European Union joined the chorus of criticism.

"The High Representative (Catherine Ashton) is deeply concerned with reports of an escalating bombing campaign in the city of Aleppo," the EU said in a statement.

"She condemns the unabated use of air strikes by the Syrian government on civilian areas."

Arab League chief Nabil al-Arabi called on "the Syrian army to stop the air bombings" of Aleppo, condemning the killing of "hundreds of innocent civilians, especially women and children".

Arabi also called on the UN Security Council "to take responsibility" to end the conflict, which has been raging in Syria for nearly three years.

The opposition National Coalition has said it will boycott a peace conference slated for January if the bombing of Aleppo does not cease.

A security source in Damascus on Tuesday defended the military's operations as necessary to "save Aleppo".

"We do not target any area unless we are 100 percent sure that the ones there are terrorists," the source said, using the regime's term for the rebels.

"The bodies you see on television are the bodies of terrorists and mercenaries, most of whom travelled into Syria from abroad."

Syria hit back at the US on Tuesday, describing it as a "one-eyed pirate" for condemning the aerial assault but "ignoring the crimes committed by the terrorists".

'Too many lives have been shattered'

In his first Christmas address, Pope Francis in the Vatican City called for peace in Syria, saying "too many lives have been shattered in recent times by the conflict in Syria, fueling hatred and vengeance".

"Let us continue to ask the Lord to spare the beloved Syrian people further suffering, and to enable the parties in conflict to put an end to all violence and guarantee access to humanitarian aid," he said.

The Syrian conflict is estimated to have killed more than 126,000 people since it first started out as peaceful anti-regime protests in 2011.

But in a new sign of confidence, Syria's Oil Minister Suleiman Abbas and General Petroleum Company signed a major oil and gas exploration deal with Russia's Soyuzneftegaz energy firm, with cooperation spanning 25 years.

The deal permits the exploration of an area of 2,190 square kilometres (850 square miles) in the Mediterranean off the Syrian coast.

The contract "is the first ever for oil and gas exploration in Syria's waters," head of the General Petroleum Company Ali Abbas told AFP, adding it would be financed by the Russian side.

The minister Abbas meanwhile said during the signing ceremony that the contract covers "25 years, over several phases," adding that: "The cost of exploration and discovery is $100 million."

Russia is one of Assad's main backers, as well as a key proponent along with the United States of peace talks slated for January in Switzerland.