UN Security Council tells Syria to focus on peace
The UN Security Council has urged Syria's leaders to fundamentally change course, more than 24 hours before a ceasefire is due to take effect.
Expressing deep concern over a report by envoy Kofi Annan, the council said it was essential to see visible signs of change in Syria's military posture.
Mr Annan told the council that military operations were continuing against civilian targets.
However, there were reports of some troop withdrawals.
Activists in Syria say that at least 37 bodies have been discovered in a mass grave in the Deir Baalba quarter in the city of Homs.
At least 60 people were killed as the army shelled a number of towns on Tuesday, including Homs, a centre of resistance to the rule of Syrian President Bashar al-Assad since the rebellion broke out in March last year.
At least 28 people were killed there, said the Local Co-ordination Committees (LCC), an activist network.
The LCC said 20 people were killed in Hama, while there were further deaths in Aleppo and Idlib in the north, Deraa in the south and in a Damascus suburb.
US Ambassador Susan Rice, who currently chairs the council, expressed dismay that the Syrian government had apparently failed to start withdrawing its troops and heavy weapons from cities by Tuesday morning, as stipulated in Mr Annan's plan.
"Members of the council are unified in their grave concern that this deadline has passed and the violence has not only continued but over the last 10 days has intensified," she said.
"The Syrian leadership should now seize the opportunity to make a fundamental change of course.
In a report to the Security Council, Mr Annan said the Syrian army was continuing operations in population centres.
"The days before 10 April should have been an opportunity for the government of Syria to send a powerful political signal of peace, with action on all aspects of the six-point plan," he wrote.
"It's essential that the next 48 hours bring visible signs of immediate and indisputable change in the military posture of the government forces throughout the country."
Speaking earlier in Turkey, after visiting a camp for Syrian refugees, Mr Annan said it was too early to say his plan had failed and that he believed the Syrian opposition "are also prepared to go along with it if the government meets its commitments to pull the troops out".
"So I think the plan is very much alive."
Ceasefire at risk
Under his plan, sponsored by the UN and the Arab League, Syrian troops were to have completed their withdrawal from population centres and stopped the use of heavy weaponry by Tuesday, ahead of a full ceasefire coming into place on Thursday morning.
Damascus had agreed to the deadline, but on Sunday demanded written guarantees first that its opponents would give up arms, along with a promise from foreign states not to fund them.
Mr Annan told the Security Council that this new demand put the cessation of violence at risk.
Permanent members Russia and China, who hold vetoes over council decisions, have prevented resolutions condemning Damascus but have backed Mr Annan's peace plan.
The BBC's Barbara Plett at the UN says there is no guarantee that they will now agree to any tougher action proposed by Western countries.
US Secretary of State Hillary Clinton said she would keep pushing Moscow - one of Syria's closest allies - to change course, saying its "refusal to join with us in some kind of constructive action is keeping Assad in power, well-armed, able to ignore the demands of his own people, of his region and the world".
Speaking during a visit to Moscow, Syrian Foreign Minister Walid Muallem said the withdrawal had begun in some areas, but that the ceasefire should be timed to the arrival of international monitors - something Mr Annan said he was working towards.
Syrian opposition representatives have said they are committed to the peace plan but that if government troops did not stop firing by Thursday, they would intensify their own operations.
Russian Foreign Minister Sergei Lavrov urged Mr Annan in a telephone call to put pressure on countries backing the Syrian opposition to make sure they stuck to the ceasefire plan.
Earlier he said the Syrian government "could have been more active and decisive" in implementing the plan, but that Mr Muallem had assured him Damascus was committed to it.