Syrian forces began a fresh offensive in the rebellious province of Homs, on Thursday according to opposition activists.
The shelling was targeting Al-Rastan city, a stronghold of the rebel Free Syrian Army (FSA), said Rami Abdel Rahman, the spokesman for the Syrian Observatory for Human Rights.
"The regime wants to destroy the city as it is totally under the control of the FSA," he said.
The province was the target of a month-long siege and bombardment by troops loyal to President Bashar al-Assad in February, according to the opposition.
The continuing violence in Syria is undermining the mission of 200 United Nations observers who are monitoring a ceasefire that went into effect on April 12.
The UN has accused both sides to the conflict of violating the truce, which is part of a plan proposed by UN-Arab League envoy Kofi Annan to end 14 months of bloodshed in Syria.
Meanwhile, a key activist group threatened on Thursday to withdraw from Syria'smain opposition umbrella grouping, saying the council has drifted away from thespirit of the Syrian revolution.
A pullout by the Local Coordination Committees from the Syrian NationalCouncil would be a blow for the group, which is already facing political andorganizational challenges in its quest to oust President Bashar Assad.
And if the SNC continues to deteriorate, it could complicate efforts for theWest and others to get behind the opposition.
Fifteen months into the uprising, Syria's opposition is still struggling toovercome infighting and inexperience, preventing the movement from gaining thetraction it needs to present a credible alternative to Assad. Its internationalbackers have repeatedly appealed for the movement to pull together and work asone unit.
The SNC, whose members are largely Syrian exiles, has tried with littlesuccess to gather the opposition under its umbrella and has alienatedminorities inside Syria, including the Kurds and Alawites. Other oppositiongroups accuse it of trying to monopolize power.
Several prominent dissidents, including Haitham al-Maleh and Kamalal-Labwani, have already quit the SNC, calling it an "autocratic" organization.
In Thursday's statement, the LCC a network of activists based both insideand outside of Syria, accused the SNC leadership of marginalizing councilmembers and acting alone on major decisions. It threatened to suspend itsmembership in the council and to withdraw altogether if its concerns are notaddressed.
"We have seen nothing except political incompetence in the SNC and a totallack of consensus between its vision and that of the revolutionaries," thestatement said.
The LCC said the council has "drifted away from the spirit of the Syrianrevolution in its quest for a civil and democratic state based on theprinciples of transparency and transfer of power.”
Earlier this week, Burhan Ghalioun was re-elected to a third, 3-month termas head of the SNC. A Sunni Muslim professor at the Sorbonne in Paris who hasled the council since its formation in September, he has been criticized bysome opposition figures of being too close to the Muslim Brotherhood and ofbeing out of touch with the reality on the ground in Syria.
Ghalioun ran against George Sabra, a Christian council member seen by manyas a better choice to soothe concerns by Syria's religious minorities, some ofwhom have remained loyal to Assad out of fear for their future in case hisregime collapses.
In a televised interview following his re-election, Ghalioun acknowledgeddivisions within the SNC and said the group was working on a new strategy.
Unlike Libya's National Transitional Council, which brought together mostfactions against Moammar Gadhafi's regime and was quickly recognized by much ofthe international community, Syria's opposition has no leadership on the groundand has not been officially recognized by significant powers.
A conference sponsored by the Arab League in Cairo to help unite thedisparate opposition was canceled this week, largely because of infightingbetween various groups.
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