Hamas's armed wing, Izaddin Kassam, on Monday announced that it was recruiting an additional 1,000 militiamen ahead of a possible IDF ground operation in the Gaza Strip. The group said that thousands of volunteers from the Gaza Strip had also asked to be recruited to the movement in the past 48 hours so that they could fight against IDF soldiers. The announcement came as sources close to Hamas said that the movement's armed wing had hardly been affected by the IDF operation that began on Saturday. The sources told The Jerusalem Post that many of the casualties in the first two days of the operation were "ordinary" policemen who had been recently recruited to various branches of the security forces. "These policemen were being enlisted to direct the traffic and fight crime," the sources said. "These are not the militiamen who are responsible for the rocket attacks on Israel." This explains why Hamas did not rush to evacuate the headquarters of the "civilian" police force in Gaza City before the IDF offensive. On the contrary, the police chiefs decided to go ahead with plans to hold a graduation ceremony for the cadets on Saturday because they did not believe that they would be targeted by Israel. According to the sources, these policemen were not members of Izaddin Kassam. As such, they were never asked to participate in armed attacks on Israel. Nor had they been asked to prepare for the possibility of having to fight against the IDF when and if it invades the Gaza Strip. "Almost all the policemen who were killed in the past three days were responsible for imposing law and order in the Gaza Strip," said Hamas spokesman Fawzi Barhoum. "Many of them were not even Hamas members." Another Hamas operative said that Izaddin Kassam, which functions as the official Hamas "army," has over 15,000 men throughout the Gaza Strip who are better trained and equipped to fight against the IDF. This is the same paramilitary force that defeated tens of thousands of US-backed Fatah policemen and security officers in the Gaza Strip in June 2007. Ever since taking full control of the Gaza Strip, the Hamas militia have been busy training its men for the possibility of an IDF invasion or a revolt by Fatah loyalists. The preparations included the construction of a vast network of underground tunnels and bunkers in various parts of the Gaza Strip, as well as the smuggling of tons of explosives and missiles across the border with Egypt. A former Palestinian Authority security official estimated that Izaddin Kassam has over 20,000 rockets and mortars, as well as tens of thousands of tons of explosives. The official said that according to reports emanating from the Gaza Strip, most of the group's commanders have survived the IDF offensive. "Israel has managed to kill only a small number of Izaddin Kassam members," said a Palestinian journalist in Gaza City. "The Kassam doesn't have offices and public security bases. This is a clandestine organization entrusted with carrying out special missions." The Hamas militiamen have now been entrusted with the task of repelling an IDF ground attack. Spokesmen for the group said on Monday that their men are determined to fight to the end. "We have many surprises for Israel," said one of the spokesmen. "We are just waiting for the ground attack to teach them an unforgettable lesson."