The Syrian military has begun closing in on an opposition-held town, which lies on key roads to the coast and northern Lebanon. Meanwhile, the Arab League has called an emergency meeting to move peace talks forward.
An assault led by government troops caused widespread damage in the town of Qusair on Sunday, according to Syrian state television and Syrian officials.
Syrian President Bashar al-Assad's army were "attacking on different fronts and destroying positions of their leaders in the south of the town," state television reported.
At least 30 people died in the fighting, 16 of whom were rebel fighters, according to the Britain-based activist group Syrian Observatory for Human Rights.
The news agency DPA reported that fighters from Lebanon's Shiite militia group, Hezbollah, provided additional support to al-Assad's army.
After hours of shelling, al-Assad's forces advanced on the town on Sunday, retaking government buildings, an official told the news agency Associated Press on the condition of anonymity. The army had left open "safe passage for fleeing civilians and the armed terrorists who want to surrender," the official said.
The Syrian military has been trying to wrest towns in the surrounding Homs province away from opposition fighters in recent weeks. Securing Qusair would restore the government's access to northern Lebanon and to the Mediterranean Sea.
Siege alarms observers
The Arab League called an emergency meeting for Thursday in response to an urgent plea from the Syrian National Coalition (SNC) to stop the "massacre" in Qusair.
"We say to the countries that are working for a political solution in Syria that allowing this invasion to go ahead in silence... will render any conference and any peace effort meaningless," the SNC said on Sunday.
"We are following the developments and changes there closely and we are prepared for every scenario," Israeli Prime Minister Benjamin Netanyahu said at his weekly Cabinet meeting.
Al-Assad dismissive of Western plans
Fighting on Sunday followed a week of deliberations between the US, Russia, Israel and other international entities eager to establish a peace plan for Syria, whose civil war recently entered its third year.
Evidence of the deployment of chemical weapons by both sides in the Syrian civil war sparked a peace conference proposal by the US and Russia earlier this month. Washington and Moscow have urged the opposition and President al-Assad's government to negotiate, with the assistance of international mediators.
kms/crh (AP, AFP, Reuters, dpa)