The Negev's large cities were targeted again by Palestinian rocket-firing crews Wednesday, as two Grads slammed into residential neighborhoods in Ashkelon, and one that hit Beersheba heavily damaged a classroom that was fortunately empty. In Ashkelon, air-raid sirens rang out to warn residents of both attacks, bringing cars to a stop and sending the few residents who had ventured outdoors scrambling for cover. The thud of a rocket landing could be heard shortly after each siren. One rocket landed at a busy intersection while a second slammed into a road. Four people were lightly wounded by shrapnel, police said. By Wednesday evening, well over 60 rockets had been fired at the South from Gaza. Police sappers managed to recover 21 projectiles. One rocket fell in Ashdod, three in Sderot, one in Kiryat Malachi, and 14 in the western Negev region. Nine rockets were fired at Ofakim and three at Netivot. Police denied reports in the morning that rockets had slammed into Yavne, more than 50 kilometers north of Gaza, and its neighbor, Gedera. Twenty people suffered shock throughout the South, police added. The relatively low number of wounded in Ashkelon was largely due to the residents' compliance with Home Front Command instructions, Ashkelon Deputy Mayor Shlomi Cohen told The Jerusalem Post. "It's proven that if people listen to the instructions, lives are saved. And the converse is true," he said. "If caught outdoors, one should hit the ground. The lower one is, the better. Finding a wall in the opposite direction of the rocket source is also good," he added. On Tuesday, an Ashkelon Municipality security department worker suffered shrapnel wounds when he wandered outside after a rocket attack. A second rocket which landed shortly afterwards caused the injuries, Cohen said, adding that residents should refrain from heading outdoors after a rocket attack. Cohen said local residents were proving to be steadfast under fire, adding, "sometimes they are too cool, to the point of being careless." He said the municipality remained concerned about the tendency of people to congregate around rocket landing zones, adding that one countermeasure being taken by city officials was to repair the damage within minutes. "Today, news crews were unable to find the hole in the sidewalk from the rocket because we repaired it minutes. This gives people nothing to look at so they go home. It also reduces psychological stress from the attacks," Cohen said. In the event of an IDF ground invasion of Gaza, Cohen said Ashkelon was braced for an initial increase in rocket attacks, but added that he believed the number of projectiles fired at his city would then decrease noticeably. "Ashkelon is their preferred target. Thanks to the air force operations, we're not dealing with a higher number of rockets," he said. Two rockets had landed south of Ashkelon on Tuesday. Ashkelon Mayor Benny Vaknin told the Post he was encouraging residents to remain there. "I don't encourage an evacuation. So long as people listen to the safety instructions, they will be all right," he said.