IDF forces moved into key areas in the central Gaza Strip Wednesday as Israel continued military operations aimed at returning captured IDF Cpl. Gilad Shalit and preventing Palestinian rocket fire into Israel. Palestinian officials said 18 people were killed, nine of them civilians. IAF aircraft and ground troops targeted a number of terror cells throughout the day, along with a pre-dawn air strike on a house where senior Hamas members were meeting. Palestinian operatives fired at least nine crude rockets at Israeli targets north and west of the Gaza Strip, military officials said. The rockets caused no damage, the officials said. IDF forces in Gaza have effectively cut the strip in two. Military officials said troops were currently focused around Khan Younis and Dir el-Balah in central Gaza. Muhammad Deif, an arch Hamas terrorist who has been on Israel's most wanted list for a decade, was wounded in an IAF strike on a house in the Sheikh Radwan neighborhood of Gaza City early Wednesday morning in which, according to Palestinians, nine members of the same family were killed, including seven children. Deif could end up paralyzed, Palestinian security officials said on condition of anonymity because they were not authorized to discuss his condition. Izzadin Kassam, Hamas's military wing, denied that Deif had been wounded. "It's completely untrue and we deny it completely," a spokesman for the terror group said. "This is an attempt to deflect attention from the massacre of civilians by the Zionist enemy." The strike took place shortly after columns of IDF armored vehicles and troops from the Givati Brigade entered Gaza through the Kissufim Crossing, once the main entrance into the former Gush Katif settlement bloc. The IAF said the Shin Bet (Israel Security Agency) provided intelligence about a meeting in the building of senior members of the Hamas military wing who were in the midst of planning attacks against Israel. Palestinian sources said that nine people were killed, including seven children, and their parents. Dozens more were wounded or trapped when the two-story house which reportedly belonged to Hamas activist Dr. Nabil al-Salmiah, collapsed. Deif was in the building at the time of the strike, but his condition was not immediately known. In addition, Ahmed Randur, one of the Hamas operatives behind the the abduction of Cpl. Gilad Shalit two-and-a-half weeks ago was also wounded. Deif has survived at least two other targeted assassination attempts in the past. He is wanted for planning and implementing numerous terrorist attacks against Israeli citizens. Minutes later, witnesses said a car in the same neighborhood was targeted in an air strike, wounding three people, witnesses said. Raed Saed, head of Hamas's military wing in Gaza City, was wounded. He was taken to a secret location for medical treatment. Abu Obeideh, spokesman for the military wing of Hamas, issued an unusually strong condemnation, using language employed only when Israel has assassinated top Hamas leaders. "We will make the leaders of the Zionist regime regret this Nazi crime," said part of his long statement. Early Wednesday morning the IAF fired on a cell of operatives near the Kissufim crossing, from where IDF forces entered into Gaza, military officials said. Shortly after the air force carried out another airstrike on a vehicle carrying rockets and explosives in Gaza City, the officials said.The air force also fired on armed Palestinians around the area of the former settlement Kfar Darom, and troops fired on armed men attempting to lay a bomb along the Kissufim route in central Gaza. Late Wednesday, troops shot and killed an armed Palestinian near IDF forces in Khan Yunis, the military officials said. Earlier Wednesday, the air force dropped leaflets over Gaza, warning Palestinians to stay clear of areas where troops were operating. "People who try to disrupt the IDF's activities, which are meant to ensure the safe return of our soldier, are doing so at their own risk," the IDF wrote in the leaflet. AP contributed to this report.