<p>Heavy fog that has shrouded parts of eastern and northeastern China has severely affected highways and flights. Many highways of northeast China's Liaoning Province have been closed for more than 12 hours. </p><p>The meteorological observatory of Shenyang, the provincial capital, issued six fog warnings from Saturday evening to Sunday . </p><p>More than 40 flights were affected at the Shenyang-based Taoxian International Airport. </p><p></p>