Afghan government forces pushed overnight into the strategic northern city of Kunduz that was captured by the Taliban earlier this week, forcing the insurgents to retreat in heavy street fighting that was still underway Thursday. The spokesman for the Afghan Interior Ministry, Sediq Sediqqi, said the operation was launched late Wednesday, with ground forces moving from the Kunduz airport where they had massed since the city fell to the Taliban _ over roads that had been mined by the insurgents. Sediqqi claimed that control of the "city was taken by 3.30 a.m.'' on Thursday but conceded that an operation "to clear the city is ongoing'' and could take some days. He told The Associated Press the battle to retake Kunduz is a joint army and police operation and that roadblocks set up by the Taliban to prevent any movement had been removed. He said essential supplies, including food and medicine, would be delivered soon to the residents. Sediqqi said around 200 Taliban fighters have been killed in the fighting so far but did not provide a figure for government casualties. Kunduz police chief, Sarwar Hussaini, said bodies of dead Taliban fighters lay on some of the city's streets but that the clearance operation was complicated because some Taliban had hidden inside people's homes. Residents reported street battles and gunfire in various areas of the city. Zabihullah, a Kunduz resident living close to the main city square, who like many Afghans prefers to use one name, said that "intense fighting is continuing on the streets of city.'' "The situation is really critical and getting worse, and I've just heard a huge explosion from a bomb near my house,'' he said, speaking to the AP over the telephone from his home. It was difficult to immediately gauge how much of Kunduz was secured by the Afghan forces. The capture of the city by the Taliban, which began with a coordinated attack Monday, had taken the government, military and intelligence agencies by surprise. On Wednesday, Afghan troops, backed by U.S. airstrikes, massed on the outskirts of the city and at the Kunduz airport in a buildup of what was expected to be a long and difficult campaign to drive out the Taliban.