AMMAN - Heavily armed forces loyal to Syrian President Bashar Assad battled rebels in the southern city of Deraa on Wednesday, while UN envoy Kofi Annan considered Syria's response to plans aimed at ending the violence.Around 20 tanks and armoured vehicles surrounded the al-Balad district of Deraa, on the border with Jordan, and fired anti-aircraft guns into buildings, activist Rami Abdelhaq said from Deraa, where the revolt against Assad began a year ago.Annan visited Damascus over the weekend and gave the Syrian president what he termed "concrete proposals" aimed at restoring peace. Annan received a response from Assad to his proposals, but questions remain and he is seeking clarification, a spokesman said on Wednesday."The Joint Special Envoy (JSE) for Syria, Kofi Annan, has now received a response from the Syrian authorities. The JSE has questions and is seeking answers," spokesman Ahmad Fawzi said in a brief statement issued by Annan's office in Geneva."But given the grave and tragic situation on the ground, everyone must realize that time is of the essence. As he said in the region, this crisis cannot be allowed to drag on," he added.Since the former UN chief's visit, the violence has continued unabated, with Syrian forces pounding built-up areas around the northern city of Idlib, in the central city of Homs and in the south, around Deraa."The attack began early this morning. The rebels are firing back, but they are outgunned," said Abdelhaq, speaking by phone, with the sound of heavy gunfire echoing in the background.A UN official has said more than 8,000 people have died in the uprising and the UN refugee agency said on Tuesday that some 230,000 Syrians had fled their homes during the past 12 months, of whom around 30,000 have sought safety abroad.