Units of police backed by the army have killed 25 Taliban militants during a series of operations across Afghanistan, the interior ministry said.During the operations launched in parts of Kunar, Nangarhar, Badakhshan, Sar-e-Pul, Kandahar, Oruzgan, Ghazni, Paktika, Paktiya, Herat and Helmand provinces, three insurgents were wounded over the past 24 hours, Xinhua quoted the ministry as saying on Tuesday.Militancy and conflicts have gained momentum in Afghanistan as warring sides have been trying to secure more turfs and consolidate their positions.