Syria's main opposition bloc has urged the international community to take action to protect civilians in the embattled city of Homs.
The Syrian National Coalition on Friday appealed to the United Nations and Western countries that have supported the opposition in Syria's civil war “to intervene immediately'' and provide food and medicine to the besieged, rebel-held areas of the central city.
Assad's forces have been bombarding Homs for five straight days, the coalition said in a statement. It said clashes between rebels and President Bashar al-Assad troops flared up again in Friday morning.
The appeal comes as opposition figures are meeting in Turkey to elect a new leadership.
Activists on Friday posted videos from al-Khalidiyeh neighbourhood purporting to show shelling that targeted the opposition stronghold.
Homs, dubbed the "capital of the revolution", has paid an enormous human and material price for the uprising against Assad's regime that began in March 2011 and has since evolved into fully-fledged civil war.
Activists claim that fighters from Lebanon's Hezbollah Shia armed movement, which has sided with Assad's forces, have been battling rebels in the city.
Hezbollah fighters helped the Syrian army capture Qusayr, a key town near Lebanon's border last month, dealing a blow to opposition fighters who have been ferrying supplies and fighters over the border.
Khalid Saleh, a spokesperson for the Syrian National Coalition, warned that the fall of Homs would jeopardise any political solution for the country.
The situation in Homs has "deteriorated tremendously" and that the Syrian regime "has its mind set on taking Homs even if that means killing tens of thousands of people," he said.
In-depth coverage of escalating violence across Syria
The coalition on Thursday began the process of selecting a new leader from five official candidates who include interim president Georges Sabra and the former president of the Syrian National Council Burhan Ghalioun.
Saleh emphasised that the new leader would have to heal rifts in the fractured coalition.
"We are at a critical juncture in the revolution," he said.
"The coalition knows it is important to respond to the challenges with which we are confronted."
Syria's main opposition has faltered since the departure of Ahmad Moaz al-Khatib in May in protest at the world's "inaction" over Syria's conflict.