At least 15 Taliban militants were killed in Afghanistan's northern province of Takhar on Thursday morning, an official said."A group of armed Taliban fighters attacked the residence of Hajji Mullah Omar, the governor of Khawja Ghar district in Hazarbagh area at around 5 a.m. today (Thursday). The bodyguards of the district governor returned fire leaving 15 attackers dead," Sunatullah Timor, provincial government spokesman, told Xinhua news agency from provincial capital Taluqan city, 245 km north of Kabul, One bodyguard of the governor was injured during the firefight which lasted a brief while, the spokesman said.Taliban militants have intensified activities since launching their so-called annual spring offensive on April 24 across the conflict-ridden Afghanistan.