A ceasefire proposed by the United Nationsis supposed to take effect in Syriain the coming days.But Syrian government forces continuedto attack opposition targetsacross the country on Friday.The Syrian Observatory for Human Rights saysmore than twenty people were killed-- most of them civilians.Opposition activities say tens of thousands of Syrianstook part in anti-government protests.The Syrian government saysit has begun withdrawing its troops from major cities.But on Thursday, U.N. Secretary-GeneralBan Ki-moon warned that Syria's conflict was growing.He said attacks by government forces on civilian areasshowed no signs of slowing.He urged President Bashar al-Assad"to show leadership and vision" and keep his promiseto end the violence by this Tuesday.The opposition is supposed to do the samewithin forty-eight hours after that.Hilal Khashan teaches political scienceat the American University of Beirut.He thinks President Assad is unlikelyto follow the peace planbecause that would give the opposition new strength.HILAL KHASHAN: "This means that Syrians will feel freeto demonstrate against the regime with impunity.This is unthinkable.Assad will never allow such developments to occur.Therefore, he will find reasonsto defeat the mission of Kofi Annan."Professor Khashan sayshe think Mr. Annan's diplomatic effortsrepresent the "last chance" that Mr. Assadwill receive from the international community.The Syrian leader agreed to the U.N. peace planon March twenty-fifth.Growing numbers of Syrians fleeing the violencehave poured into neighboring Turkey.Turkish Foreign Minister Ahmet Davutoglucalled the U.N. secretary-general on Fridayto express concern about the growing number of refugees.The United Nations says more than nine thousand peoplehave been killed since the uprisingagainst Mr. Assad began thirteen months ago.Anti-government opposition groups held protestsin a number of towns and cities after Friday prayers.(SOUND)Opposition videos showed hundreds of protestersdemonstrating on Friday in the northern city of Aleppo.Videos also showed large protestsin several other areas and in Damascus.Witnesses reported heavy government shellingin the city of Homs Friday.Parts of Homs have come under government shelling for weeks.Al Arabiya television reported that government troopsstormed Douma outside Damascusand made large numbers of arrests.Government forces have temporarilyretaken parts of Douma several times,only to lose control later.Former U.N. Secretary-General Kofi Annan proposed the peace plan.He said Thursday that there was little progresson ending the conflict.Russia and China, both allies of the Syrian government,have increased pressure on Syrian officials to follow the plan.Syria blames much of the violence on what it calls"terrorists" supported by "Arab and Western countries."It says terrorist acts increased after the governmentreached an agreement on Mr. Annan's peace plan.And that's IN THE NEWS in VOA Special English.