A countrywide air raid siren kicked off the third day of the biggest-ever war drill to be held in Israel - though the exercise was quickly followed by a number of complaints from residents who said they could not hear the alert. A police spokeswoman confirmed that regional councils had received calls from people who could not hear the sirens, adding that local authorities that helped operate the sirens welcomed the reports as an opportunity to repair glitches. The IDF Home Front Command said uncovering faulty sirens was one of the aims of the exercise. "We are currently collecting and analyzing the data from the countrywide siren drill this morning. It should be noted that one of the purposes of this drill is to test and map the location where the sirens are not heard in order that the problem be fixed," the Home Front Command said in a statement. Siren hiccups also occurred in the Gaza border region. Two communities heard the alert, despite a decision to exclude the area from the drill due to the ongoing rocket attacks there. Schools around the country simulated aerial bombardment exercises during the alert, instructing children on the correct position to take during a missile strike. Emergency TV and radio broadcasting interrupted regular programming earlier in the day testing a number of emergency contingency plans. The Home Front Command and emergency services simulated a rescue operation in which victims trapped under rubble were evacuated in Jaffa and in Jerusalem, while Afula and Beersheba were the scenes of mock-chemical attacks. During Monday's simulated three-front missile and rocket attack on the country, 100 civilians were "killed," while Ben-Gurion International Airport also came under "attack" and a military airfield was used as a substitute landing strip civilian airliners. The Environmental Protection Ministry practiced dealing with a hazardous material accident as a result of a missile attack, such as a direct hit on a factory, as part of the nationwide Home Front Command drill on Tuesday. The ministry's Hazmat unit's job is to locate and identify any hazardous materials involved in an attack and to monitor and measure the concentration of the material in the air and assess the threat. The unit is also charged with making suggestions to the official managing the incident on what to tell the public and how to rehabilite the affected area. The unit also follows up to make sure rehabilitation is actually done. The ministry also inaugurated a new situation room in the government building in Ramle. Day four of the drill will introduce the nightmarish scenario of widespread missile attacks across Israeli cities. Haifa police and rescue services will train for the possibility of an explosion at a chemical plant near the city's port. Ehud Zion Waldoks contributed to this report.