At least 11 pro-government tribesmen and seven militants were killed when the Taliban launched an attack on a security checkpoint in the eastern Afghan province of Ghazni, sources said Thursday.An unknown number of militants raided the checkpoint in Andar district, overnight, resulting in a fierce fighting for hours, provincial government spokesperson Shafiq Nang told Xinhua.The Taliban has been waging an insurgency since its regime was toppled by a US-led invasion in late 2001.The militant group has intensified attacks with a string of bombings over the past couple of months as the Afghan National Security Forces assumed the full security responsibility from NATO-led troops after a four-year security transition process ended Dec 31.