At least six Afghan security forces and eight Taliban militants were killed on Tuesday after heavy fighting broke out in the country's Farah city.Taliban militants launched a major offensive at around 2.40 a.m. from northern and western neighbourhood of Farah, in a coordinated effort to seize full control of the city, an official told Xinhua news agency.Interior Ministry spokesman Najib Danish said that a counter-offensive operation was ongoing and the security forces were trying to bring the situation under control."There is no fear of collapsing of the city to the hands of the insurgents," Danish said.However, another official said that "the Taliban captured several security checkpoints inside and around the city."The situation is tense. Most people are staying indoors. The streets are deserted. Gunfight, airstrikes and explosions are taking place around the city," he said.Several security personnel, including provincial Deputy Police Chief Abdul Razaq, were injured during the fighting.