Dense fog delayed 35 flights at an airport in the central Chinese city of Changsha, Hunan province, Tuesday, leaving about 3,000 passengers stranded, airport authorities said. Thick fog blanketed the Changsha Huanghua International Airport Tuesday, reducing visibility to less than 50 meters, the airport\'s operators said. The fog forced the airport to shut down for more than three hours, they said. Road traffic was also affected by the thick fog, adding woes to the current peak travel period as millions of migrant workers have hit the road to look for jobs in big cities since the week-long Chinese Lunar New Year ended.