CAIRO (AFP) - Rain and sandstorms that battered Egypt at the weekend killed at least 31 people, officials said Monday, adding the toll could rise as rescue workers were still sifting through two collapsed buildings. The bodies of six workers were pulled out Monday of the debris of a six-storey textile factory that crumpled under heavy the previous day in the northern port city of Alexandria, the officials said. And one worker among 10 who had been wounded in Sundays accident died of his injuries, bringing the overall toll of those killed to 10, the officials said. Rescue workers were still looking for about a dozen workers who are thought to be still trapped under the mangled building, they added. In the Nile Delta city of Tanta, a child was killed and nine people hurt when a five-storey residential building came down on Sunday, leaving one person trapped under the rubble. Building collapses are relatively frequent in Egypt where construction guidelines are flouted and extra floors are often added to buildings without planning permission. Twenty people were killed and more than 40 injured in road accidents Sunday across Egypt blamed on poor visibility from heavy rains and sandstorms, officials said. Meanwhile, a tug boat was trying to pull to safety on Monday an Italian cargo ship stranded off Egypts northwestern coast with 21 crew on board and 38 containers of toxic paint and resins, the Italian news agency Ansa reported. The ship had broken down three days earlier off the coast of Marsa Matruh. Egypts main ports in Alexandria and the Red Sea opened on Monday a day after authorities closed them due to high winds, low visibility and heavy rains, officials said. Maritime traffic at the Suez Canal was restored after the entry of south-bound ships was barred on Sunday and north-bound traffic was limited from the waterway, which links the Mediterranean to the Red Sea.