NEW : U.N.-Arab League secretary-general accepts the Homs envoy 's resignation . Syrian rebels and the government agreed to a truce Tuesday . `` The resignation of Lakhdar Brahimi is further proof of the failure of international efforts to end the horrific bloodshed in Syria , '' said Andy Baker , region program manager for Oxfam on the Syrian crisis . On Monday , government troops fired upon an opposition neighborhood in Homs . On Monday , rebels shelled two pro-government neighborhoods in Syria , opposition says .
NEW : U.N.-Arab League secretary-general accepts the Homs envoy 's resignation . Syrian rebels and the government agreed to a truce Tuesday . On Monday , government troops fired upon an opposition neighborhood in Homs . On Monday , rebels shelled two pro-government neighborhoods in Syria , opposition says .