The Syrian government has not kept its promises on a crucial ceasefire deal and continues to station tanks and troops in residential areas, UN Secretary General Ban Ki-moon has said.
In a letter to the UN Secretary Council, Ban outlined continued abuses by government forces, including an apparent attempt to hide armoured vehicles under plastic sheets.
"The Syrian government has yet to fully implement its initial obligations regarding the actions and deployments of its troops and heavy weapons, or to return them to barracks," the letter said.
He detailed one case of an armoured personnel carried near Damascus which "was hidden, covered by a plastic sheet".
Ban also described the moment on Wednesday when "a crowd that was part of an opposition demonstration forced United Nations vehicles to a checkpoint".
"Subsequently, the crowd was dispersed by firing projectiles," he said. "Those responsible for the firing could not be ascertained by the United Nations Military Observers."
Ban also said that "no substantive progress" had been made in delivering humanitarian aid to more than one million people in need.
But despite his concerns Ban called for a monitor mission of 300 UN observers to be sent to the country. He said the team would fan out across Syria to keep track of the tattered truce, which has been in place for just over a week.
Syrian officials have agreed to the deal, signing an accord with a UN advance team who yesterday were surrounded by anti-government protesters who were subsequently fired upon.
The UN Security Council is yet to vote on the plan, amid concerns that the observers could be in danger if the situation continues to deteriorate.
In his letter, Ban said an "opportunity for progress" still remained and that violence had fallen "markedly".
The UN monitor mission would be a "nimble presence", he said, which "would be deployed incrementally over a period of weeks, in approximately ten locations" to "rapidly observe, establish and assess the facts and conditions on the ground".
Above: Unverified video of shelling in Homs uploaded by Syrian activists
Despite the ceasefire violence has been reported across Syria.
Activists working with Avaaz have reported heavy shelling in the city of Homs, and published video purporting to show the town under fire.
Meanwhile Britain said it will provide an additional £4 million in aid for refugees displaced by the fighting in Syria.
Half the funding will go to humanitarian agencies working to provide medical assistance to people injured in the fighting. The rest will be distributed through the United Nations High Commissioner for Refugees.
International Development Secretary Andrew Mitchell said: "This new British support will ensure that thousands of people receive potentially life-saving help, whether injured as a direct result of the regime's violence against its own people or trapped by the fighting and denied the medicines they need.
"It will also help to meet the basic needs of hundreds of frightened families who have fled home with nothing."
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