It was a phone call Ibrahim Mahmoud says he'll never forget. The woman on the other end, speaking in Hebrew-accented Arabic, accused the appliance store owner of being a member of Hamas and informed him the IDF would bomb his house. Hours later, after he had already moved 20 relatives out of the four-story building, she called back to tell him she had made a mistake. "Be safe," she said and hung up, according to Mahmoud. Dozens of other Palestinians have recently received similar phone calls, many of them on target, in a new tactic the army said is meant to reduce civilian casualties in its monthlong offensive in Gaza. Palestinian officials dismissed the army's claim that the phone calls are meant to reduce deaths. The military is also dropping leaflets from aircraft, warning people to stay away from terrorists. The army has also taken over Hamas radio frequencies for short periods of time for the same purpose. Israel launched its offensive after a Hamas-linked group killed two soldiers and captured a third in a cross-border raid on June 25. Since then, more than 120 Palestinians have been killed. On Wednesday, Palestinians suffered their highest one-day casualty toll when the army killed 23 people, among then 16 terrorists as well as a mother and her two small daughters. The army has said it regrets the civilian casualties, but accuses terrorists of operating from residential areas. So this week, about 1,000 residents in the southern Gaza city of Khan Younis answered their phones and listened to a recorded message by the IDF warning them against harboring operatives or hiding weapons. Government officials said some of the calls reached hospitals and government offices. The Palestinian phone company said the numbers were apparently picked at random. The army said the calls are to specific homes or areas, but refused to say how it picked the numbers. Hamas government spokesman Ghazi Hamad dismissed the army's claim that the phone calls were meant to reduce casualties, calling them a "criminal act" meant to drive people out of their homes, paralyze the government, and "demoralize" the population. Othman Shbeir, a Palestinian security officer from Khan Younis whose terrorist brother was killed in an airstrike recently, initially dismissed as a joke the telephoned warning he had received, until neighbors told him that a nearby house of an Islamic Jihad activist had been bombed the same night. Days later, his three-story house is empty. "It is better if they just bring the house down," he said. "We are living in terror and no one can come near the house."