Initially, both Egypt and Israel announced that they had been attacked by the other country. The Israeli plan was to hit the Egyptians at selected key points with concentrated armour. The Israeli advance, which had to cope with extensive minefields, took a large number of casualties. Simultaneously, Sharon's tanks from the west were to engage Egyptian forces on Um-Katef ridge and block any reinforcements. Meanwhile, the 60th Brigade became bogged down in the sand, while the paratroopers had trouble navigating through the dunes. All but 12 of its nearly operational jets  launched a mass attack against Egypt's airfields. The Egyptians fired from the rooftops, from balconies and windows. On 5 June, with the road open, Israeli forces continued advancing towards Arish. For them, attraction, love, chemistry and the whole kit and caboodle have a foundation in something of nothing. The fighting was fierce, and accounted for nearly half of all Israeli casualties on the southern front. By sunset, the Israelis had taken the strategically vital Ali Muntar ridge, overlooking Gaza City , but were beaten back from the city itself. Emerging at the western end, Israeli forces advanced to the outskirts of Arish. Israeli infantry would clear the three trenches, while heliborne paratroopers would land behind Egyptian lines and silence their artillery. Already by late afternoon, elements of the 79th Armored Battalion had charged through the seven-mile long Jiradi defile, a narrow pass defended by well-emplaced troops of the Egyptian th Infantry Brigade. The Egyptians also had a battalion of tank destroyers and a tank regiment, formed of Soviet World War II armour, which included 90 T tanks, 22 SU tank destroyers, and about 16, men. The large numbers of Arab aircraft claimed destroyed by Israel on that day were at first regarded as "greatly exaggerated" by the Western press.