Afghan forces were conducting clearing operations in Kunduz on Tuesday, warning that Taliban militants were hiding in civilian homes after an hours-long assault on the city repelled with the help of NATO air support. Helicopters hovered over the strategic provincial capital and special forces were stationed in the main square, but with fighting still in the outskirts residents remained fearful and most shops and businesses were shuttered, a correspondent there said. The assault launched early Monday came just over a year after militants briefly seized the provincial capital, and as President Ashraf Ghani flew to Brussels to meet world leaders for a crucial foreign aid conference. "Security forces have intensified their clearing operation since last night," interior ministry spokesman Sediq Sediqqi told a press conference in Kabul, adding that fighting was ongoing in the city's outskirts. He said at least 30 Taliban fighters had been killed, contradicting an earlier police source who put the figure at "hundreds." A defense ministry spokesman said three Afghan soldiers had been killed and seven wounded in the fighting, while hospital officials in the city said one civilian had been killed and around 40 wounded. Kunduz provincial governor Assadullah Omarkhil said the operation was still ongoing. "It is a bit slow because the Taliban are using people's houses to hide," he said, asking residents to stay in their homes. NATO forces in Afghanistan said the Afghan government "controls Kunduz," and that there had been one "US air-to-ground engagement" by helicopter defending Afghan forces on the outskirts of the city. But the Taliban insisted that "heavy attacks" were still underway, with a spokesman saying on Twitter that the militants were advancing. The insurgents are known to exaggerate their claims. On Monday residents had reported being trapped in their homes by intense fighting as the sound of explosions echoed across the city, with provincial officials voicing fears it could fall. Meanwhile, 12 Afghan policemen were killed by Taliban fighters who attacked checkpoints around Lashkar Gah, the capital of southern Helmand province. Haji Gran, chief of the city's police district 2, said on Tuesday that the Taliban attacked four checkpoints late on Monday, killing 12 and wounding another 11 policemen. Lashkah Gar has been under threat of Taliban takeover for months as insurgents have been slowly taking control of Helmand since the beginning of the year. The provincial spokesman, Omar Zwak, says Khanashin district in the south of the province had fallen to the Taliban after coming under attack on Monday. He says that in recent days, around 45 members of Afghan security forces have been killed in fighting there and more than 15 have been taken captive.