MADINA: A storm of dust and sand brought air traffic in Madina to a halt Thursday morning after visibility was reduced to below 100 meters. Weather authorities issued a warning to the airport and other facilities, leading to the temporary suspension of all flights as well as the deployment of extra traffic police on the city's roads. A Health Affairs official said hospitals were put on alert ahead of an expected rise in visits from bronchitis and asthma sufferers and persons with chest complaints. Medics were warned to expect an increase in motor accident victims. Muhammad Alem from the Meteorology and Environmental Protection Agency said the wave of dust and sand, which also hit Riyadh, Qassim, Hail and eastern parts of the Kingdom, was caused by air depression over Sudan. He expected conditions to have returned to stability by Thursday night. In the Eastern Province the sandstorm brought traffic in Abqiq to a halt. Six fatal accidents were registered while hospitals also saw a surge in the number of patients suffering breathing difficulties. A hospital official advised parents to keep children indoors and wear protective face masks.