The United Nations Secretary General, Ban Ki-moon, says he's gravely alarmed at reports from Syria that the government is continuing to shell populated areas.
The Syrian government and rebels have traded blame for the latest violence which killed 16 people in the city of Hama.
Mr Ban says the Syrian government is in contravention of the peace plan it had agreed to and which had been endorsed unanimously by the Security Council.
Antonio Guterres, UN High Commissioner for Refugees, says he believes events such as a deadly explosion in Hama on Thursday will lead to increased rate of refugees attempting to flee Syria.
Mr Guterres told the BBC's Katty Kay that his mandate required strict independence, in order to preserve asylum spaces in all countries, especially as "the old crises never die".
"The international community has not shown the capacity to prevent conflict and to address conflict, solving it quickly before it becomes protracted and before the humanitarian impact becomes sometimes devastating."
Ahmad Fawzi, the spokesperson for the international envoy Kofi Annan, says there is no ceasefire in Syria.
