BEIRUT (AP) -- Government troops shelled rebel-held areas in central Syria on Friday, killing at least four people, activists said, as the United States, Europe and Arab nations met in Tunisia to seek ways to ease the crisis.
More than 70 countries will participate in Friday's "Friends of Syria" meeting, which is expected to press Syrian President Bashar Assad to agree to a cease-fire and allow for humanitarian aid to reach the areas that have been hardest-hit by his security forces.
In the run up to the conference, American, European and Arab officials said the group would likely impose harsher sanctions if Assad rejects the cease-fire and predicted that his opponents would grow stronger if he remained in power.
And in an effort to bring an end to the violence, the U.N. announced that former Secretary General Kofi Annan will be the joint U.N.-Arab League envoy to deal with the crisis.
In a statement, Annan said Friday he would try to "help bring an end to the violence and human rights abuses, and promote a peaceful solution" in Syria. He expressed hope the Syrian government and opposition groups will cooperate with him in his efforts.
The Tunisia meeting is the latest international effort to end the crisis, which began when protesters, inspired by the Arab Spring uprisings elsewhere, took the streets in some of Syrian impoverished provinces nearly a year ago to call for political change.
Since then, Assad's security forces have violently repressed the uprising, blaming it on Islamic extremists and armed gangs, while members of the originally peaceful opposition have taken up arms.
The U.N. estimated in January that 5,400 people had been killed in the conflict in 2011. Hundreds more have died since. Syrian activists say the death toll is more than 7,300. Overall figures cannot be independently confirmed because Syria has prevented most media from operating inside the country.
Also Friday, U.N.-appointed investigators in Geneva said they had complied a list of Syrian officials accused of crimes against humanity in the crackdown. The list reaches as high as Assad.
Russia and China have long opposed foreign intervention in Syria.
Alexei Pushkov, a Russian lawmaker, said Friday after meeting Assad recently that the Syrian president sounded confident and demonstrated no sign he would he step aside. Pushkov warned that arming the Syrian opposition would fuel civil war.
"Assad doesn't look like a person ready to leave, because, among other things, there is no reason for him to do that as he is being supported by broad layers of the population," Pushkov said, according to the RIA-Novosti news agency.
Four people died Friday in the renewed shelling of the Baba Amr neighborhood of Homs, activists said, the latest of hundreds killed there in recent weeks. The neighborhood, under siege and intense shelling for three weeks, has become the center of the revolt.
The British-based Observatory for Human Rights said troops were also attempting to storm Rastan, a besieged rebel-held town just north of Homs. He said the town was being shelled and reported heavy clashes between troops and army defectors who destroyed two armored personnel carriers.
Amateur videos posted on the Internet by activists showed black smoke rising from residential areas of Baba Amr and debris littering its slum-like apartment blocks.
Parts of Homs, Syria's third-largest city, have been under a fierce government attack for nearly three weeks.