BEIRUT (Reuters) - The Syrian government and rebels traded blame on Thursday for a huge explosion which killed 16 people in the city of Hama, as a two-week-old U.N.-backed ceasefire looked increasingly fragile.
U.N. Secretary-General Ban Ki-moon accused Damascus of breaking its pledge to withdraw heavy weapons and troops from towns, saying he was "gravely alarmed by reports of continued violence and killing in Syria."
Syria blamed "terrorist" bomb-makers for Wednesday's blast. Information Minister Adnan Mahmoud also accused rebel militiamen of repeated violations of the ceasefire and said Damascus was "reserving the right to respond to any violation or attack", state news agency SANA reported.
The British-based Syrian Observatory for Human Rights said the cause of the explosion was unclear, but also gave a death toll of 16. The Local Coordination Committees, a grassroots opposition group, said more than 50 people had been killed by what it said was a military rocket.
The blast in Hama, a centre of unrest against President Bashar al-Assad, has added to doubts about a ceasefire brokered by U.N.-Arab League envoy Kofi Annan, who, like Ban, says Assad has not ordered troops and tanks back to barracks as promised.
But outside powers are deeply divided on how to shore up the ceasefire, which has led to only a small reduction in violence in the 13-month-old uprising, during which the United Nations estimates Syrian forces have killed 9,000 people.
France, leading Western calls for tougher action against Assad, says it is planning to push next month for a "Chapter 7" Security Council resolution if Assad's forces do not pull back.
Chapter 7 of the U.N. charter allows the Security Council to authorize actions ranging from diplomatic and economic sanctions to military intervention. In the case of Syria, Western powers have said they intend to push for an arms embargo and sanctions if Damascus fails to comply with the Annan plan.
Russia and China have made clear that they would veto any attempt to authorize Libya-style military action in Syria and have resisted the idea of sanctions. The Western powers on the Security Council have signaled that there is no appetite in the West for authorizing the use of force against Syria.
U.S. Ambassador to the United Nations Susan Rice reiterated on Thursday that Assad's government has not lived up to its commitment to halt the fighting and elaborated on the kind of "Chapter 7" action Washington is considering.
"We have talked about the importance of this council being prepared to consider sanctions in the event that the Assad regime continues to violate every commitment it makes," Rice told reporters in New York.
The Arab League issued a statement calling on the Security Council to take immediate action to protect civilians but cut a reference from an earlier draft that would have recommended "Chapter 7" action by the 15-nation body.
Russia - which won a strong foothold in the Middle East through its close ties with Assad's government - suggested, however, that it was more inclined to share at least some of Damascus' description of the current fighting [ID:nL6E8FQ9VM].
"We call upon the Syrian side to carry out in full its obligations," Russian Foreign Ministry spokesman Alexander Lukashevich told a weekly briefing. "Nonetheless ... there is another side in Syria, opposition groups, which have in essence shifted to tactics of terror on a regional scale."
MONITORS TRICKLING IN
The ceasefire appears to be breaking down across Syria.
An activist said seven civilians and two rebel militiamen were killed in fighting in the eastern city of Deir al-Zor, while a resident of Zamalka on the outskirts of Damascus reported intense gun-battles.
"There have been heavy clashes today, really heavy over the past couple hours," the man said. "I couldn't get close enough to see. There are checkpoints everywhere."
SANA said a school headmaster was blown up in a booby-trapped car in the northern city of Aleppo and an "armed terrorist group" shot dead four members of the same family in Erbin near Damascus.
It also said two members of the security forces were killed in Deir al-Zor.
"Armed terrorist groups have escalated the crimes of killing, massacres, explosions, kidnappings and assassinations against civilians and law-enforcement members," Information Minister Mahmoud said in a statement reported on SANA.
In all, Damascus says 2,600 of its personnel have been killed in the fighting.
U.N. monitors charged with policing the ceasefire are trickling in, and two are now based permanently in Hama, where many thousands of people were killed when Assad's late father, Hafez al-Assad, crushed an armed Islamist uprising 30 years ago. Two observers are also staying in the battered city of Homs.
Activists have been dismayed at the pace of the observer deployment. A senior U.N. official said this week it would take a month to put the first 100 monitors on the ground, though the world body is working to speed up the pace of deployment.
The main reasons for the slow pace are national bureaucracies in approving and freeing up officers to join the U.N. force, called UNSMIS; the need to train them before deploying; and bureaucracy on the part of Damascus in issuing visas. Syria has already refused to allow one officer to join UNSMIS because of his nationality, U.N. officials say.
Only 15 are in place so far out of an envisaged full-strength team of 300 to be led by Norwegian General Robert Mood.
SANA said four monitors from Russia, Syria's most powerful ally, were on their way.
Syria says it has completed withdrawing tanks and troops from populated areas in line with Annan's peace plan, but the former U.N. chief said on Tuesday Damascus had failed to meet all its commitments and the situation remained "unacceptable".
His team said they had satellite photographs confirming their views.
The United Nations is drawing up a major humanitarian effort for more than a million people affected by the conflict. A report seen by Reuters on Thursday said sewage networks had been damaged and water contaminated, setting the stage for outbreaks of water-borne diseases such as cholera.
(Additional reporting by Oliver Holmes in Beirut, Stephanie Nebehay in Geneva, Louis Charbonneau and Michelle Nichols at the United Nations, Yasmine Saleh and Ayman Samir in Cairo; editing by Myra MacDonald and Mohammad Zargham)
