Tel Aviv, Oct 28 : The Isreal Defense Forces (IDF) has warned the residents of Gaza that the city has now turned into a 'battlefield' with the IDF increasing its areal strikes. IDF leaflets that were dropped in large numbers in Gaza read, "Gaza city has become a battlefield. Shelters in Northern Gaza and Gaza governorate are not safe." The leaflets also mentioned that it is not safe to stay in Gaza anymore as the IDF urged the residents to move to the Southern area and to evacuate immediately. The leaflets were dropped from IDF fighter jets. In aerial operations on Friday night and early Saturday morning, the IDF reportedly destroyed around 140 underground tunnels of the Hamas. The IDF and Shin Bet have also said that the Al-Shifa hospital in Gaza was one of the major terror operation centres for the Hamas. /IANS