Iraqi opposition forces clashed with units of Saddam Hussein's Republican Guard last night on the outskirts of Kirkuk in northern Iraq, according to the Iraqi National Congress, a longstanding resistance group. The Iraqi rebel troops have taken up fortified positions in preparation for an offensive against Saddam's forces, said the umbrella group's Washington, D.C., director, Entifadh Quanbar. The resistance troops came under fire from Republican Guard units along the roads leading to Taqtaq and Chamchamal, he said. There were no reports of casualties. The Iraqi forces opposing Saddam are working in coordination with coalition troops. "They can play a huge...