RIYADH — All schools in Riyadh region as well as the Eastern Province will remain closed on Thursday in the wake of the sandstorm hitting the region, the Saudi Press Agency reported quoting officials. Muhammad Al-Murshid, director general of the education department in Riyadh region, said directives have been issued to suspend all classes in public and private schools on Thursday as a precautionary measure against the sandstorm hitting the region since Tuesday. Saeed Al-Bhas, official spokesperson of the education department in the Eastern Province, said all schools have been asked to suspend classes on Thursday due to the bad weather. Visibility at King Fahd International Airport fell to almost zero resulting in the suspension and delays of many international and domestic flights. The schools will remain suspended on Thursday in Riyadh city as well as in various governorates in the province, including Diriyah, Horaimilah, Thadeq, Remah, Darmaa, and Muzahamiyah, Al-Murshid said. As confirmed by weather reports, the sandstorm hit Riyadh on Tuesday and Wednesday and authorities advised drivers to be careful. Riyadh Traffic Department spokesman Col. Hasan Al-Hasan urged residents to be careful while driving on the streets as the sandstorm was preceded by fog, reducing visibility. The Ministry of Health advised citizens and expatriates, especially those affected by asthma and other respiratory diseases, not to venture out of homes. In a press statement on Wednesday, the Media Information and Health Awareness Center under the ministry urged the public to stay indoors during sandstorm, and not to venture out without masks. It cautioned that sandstorms are a major cause of bacterial and viral infections, besides posing serious health risks especially for those with pulmonary problems. The statement also called for the people to shut doors and windows of houses. The ministry said that health centers and hospitals across the Kingdom have been readied to receive any emergency cases. The Presidency of Meteorology and Environment (PME) had warned the public that a dust wave accompanied by poor visibility would sweep several regions of the Kingdom, especially the central, eastern and north eastern regions of the Kingdom on Wednesday. Abdullah Al-Musned, associate professor of geography at Al-Qassim University, cautioned that a ‘dark storm' coupled with cold wind will sweep the northern part of the Kingdom. Speaking to SPA, he said that the dark storm might prevail until Thursday, especially in the northern and southern regions.