Beirut: The United States chided Russia for sending missiles to the Syrian government as plans for a peace conference promoted by Washington and Moscow were hit by diplomatic rifts over its scope and purpose.
Sectarian bloodshed in neighbouring Iraq during Friday prayers, a hacking attack on a Western newspaper by sympathisers of Syrian President Bashar al-Assad and defiant comments by a rebel commander filmed eating a slain soldier's flesh were all reminders of how the two-year-old civil war is metastising.
But the divisions among world powers that have prevented a coordinated resolution were also again on display, just 10 days after Russia and the United States agreed to bury differences and push for an urgent international conference to end the war.
The most senior US military officer, General Martin Dempsey, described Russia's recent delivery of anti-ship missiles to Assad as "ill-timed and very unfortunate" and risked prolonging a war which has already killed more than 80,000 Syrians and which the UN said had driven 1.5 million abroad.
While not responding directly to US assertions that it had sent Yakhont missiles, a spokesman for President Vladimir Putin said Russia would honour contracts to supply Syria, which has been a customer for Moscow's weaponry since the Cold War.
"It's at the very least an unfortunate decision that will embolden the regime and prolong the suffering," Dempsey, the chairman of the Joint Chiefs of Staff, told reporters.
With a range of 300 km (200 miles), the Yakhont could prove a threat to warships in the Mediterranean, should, for example, Western powers abandon their deep reserve and intervene to offer air support to the rebels, as they did in Libya two years ago.
No date has yet been agreed for the international meeting, which appears to face growing obstacles. UN Secretary-General Ban Ki-moon met Putin in Russia on Friday and said the conference should take place as soon as possible.
But highlighting the diplomatic conundrum it poses, France spelled out explicitly on Friday that it would oppose any meeting if Assad's regional ally Iran were invited - contrary to the Russian position that Tehran should be part of a solution.
The rebels and key Arab and Western backers will meet in Amman on Wednesday to discuss how to approach a conference. But it is also far from clear that Assad's opponents can forge a united front or agree to meet the president's representatives.
After months of diplomatic stalemate, Washington and Moscow have been pushed to convene the conference by the rising death toll and atrocities, signs of escalation across Syria's frontiers and suspicions that chemical arms may have been used.
Three weeks ago, Israeli air strikes near Damascus that were said to target Iranian weapons heading for Lebanon drove home the risk of the Syrian conflict spreading further afield. As much was true of bombings last week across the border in Turkey.
On Friday, dozens of Iraqis were killed in bombings which fuelled fears that the increasingly sectarian war in Syria, where Sunni Islamists are a part of the rebellion and Assad's Alawite minority is backed by Shi'ite Iran, could plunge Iraq back into its own bloody civil conflict between Sunni and Shi'ite Muslims.
Two bombs exploded outside a Sunni mosque in the city of Baquba as worshippers left Friday prayers, killing at least 43 people in one of the deadliest attacks of recent months.
Several other bombings claimed lives around the country - with 19 killed near a commercial complex in the west of Baghdad. Attacks on Sunni and Shi'ite mosques, security forces and tribal leaders have mounted since troops from the Shi'ite-led Iraqi government raided a Sunni protest camp near Kirkuk a month ago.
London's Financial Times became the latest Western media outlet to be targeted by online activists who support Assad.
Stories on the FT's website had their headlines replaced by "Hacked By Syrian Electronic Army" and messages on its Twitter feed read: "Do you want to know the reality of the Syrian 'Rebels?'" followed by a link to a video that purports to show members of the al Qaeda-linked Nusra Front rebel group executing blindfolded and kneeling Syrian soldiers.
The video could not be independently verified.
Following another of many Internet videos that have caused concern over deepening communal hatreds, a rebel commander who was filmed apparently cutting out and biting into the heart or other organ of a dead solder made a statement on Friday.
"I am ready to be held accountable for my actions, on condition that Bashar and his shabbiha (militias) are tried for crimes they committed against our women and children," the man known as Abu Sakkar said in a new video posting.
"I send this message to the world: if the bloodshed in Syria does not stop, every Syrian will become Abu Sakkar."
Asked by the unseen interviewer why he mutilated the body, he said the soldier's phone contained video clips of him raping women, burning bodies and cutting off the limbs of captives.
A Western diplomat at the United Nations in New York said the target date for the peace conference was June 10-15, but it depended on the readiness of the Syrian parties. An alternative plan would be to hold an international conference and then have the Syrians meet at a later date when they are prepared.
The Russian arms transfer could intensify a push by some US lawmakers for the United States to deepen its role in Syria, particularly after President Barack Obama's government acknowledged preliminary intelligence that Assad's forces likely used chemical weapons - something Obama has called a "red line".
"We can watch from the sidelines as the scales are tipped in Assad's favour, or protect US national interests by supporting the armed opposition striving to build a new Syrian future," said Senate foreign relations committee chairman Robert Menendez.
But many US officials fear Western weapons could fall into the wrong hands. Obama said Thursday he would consider both diplomatic and military options to pressure Assad, but insisted US action alone would not be enough to resolve the conflict.