DAMMAM — Moderate to heavy rainfall, accompanied by high-speed winds, hailstones, and torrential rain, witnessed in many cities and governorates of the Eastern Province on Monday amid forecast of the possibility of extending rain depression, which struck parts of the Sultanate of Oman and the United Arab Emirates, to the region. The National Center of Meteorology (NCM) said that the rainy weather and dust conditions led to lack of horizontal visibility in the western parts of the Qassim region and in the Riyadh region, including the Riyadh city. This condition is expected to affect the rest of the governorates of the Riyadh region as it moves in the southern direction. The center urged the public to exercise caution and follow the instructions issued by the concerned authorities. The NCM noted that that this inclement weather condition would result in light rainfall, accompanied by a near-zero level of horizontal visibility, in the Riyadh city as well as in the governorates of Diriyah, Huraymila, and Durma in the Riyadh city. The General Directorate of Civil Defense urged the public to exercise caution and follow instructions due to the climatic fluctuations witnessed in the Eastern Province and many other parts of the Kingdom. It urged to stay away from water bodies, low lying areas, valley, and dams. Schools in the Eastern Province suspended in-person classes due to the heavy rains that flooded many parts of the region. The Eastern Province Mayoralty closed the vital King Fahd Road tunnel in Dammam as part of the precautionary measures due to the high intensity of rain and strong winds that the region is witnessing. The tunnel will be opened as soon as the weather conditions stabilize, it said in a statement. The NCM had warned of continued heavy rains in the regions of Jazan, Asir, Al-Baha, the Eastern Province, and parts of Hail and Al-Jouf, expecting the cumulative weekly rains to reach about 25 mm in some areas. A rain depression deepened over the Sultanate of Oman on Tuesday, bringing heavy rain and hail to most of the northern governorates as well as to parts of UAE. Heavy rains and flash floods have swept parts of the Gulf region, killing at least 18 people in Oman and causing travel disruption in the UAE. In Oman, the death toll announced on Tuesday included at least nine schoolchildren and their driver whose vehicle was washed away by the floodwaters in Samad A'Shan on Sunday. The National Committee for Emergency Management in Oman said rescue teams were still searching for two missing people.