It is estimated that between 7,000 and 9,000 Israeli artillery shells were fired into Gaza between September 2005 and June 2006, killing 80 Palestinians in 6 months. On the Palestinian side, over 1,300 Qassam rockets have been fired into Israel from September 2000 to 21 December 2006. Israeli forces also continued to search for tunnels, used by militants to smuggle weapons, as well as monitor operations at checkpoints (with some assistance from the European Union at Rafah) for security reasons, specifically possible weapons transfers and uninhibited return of exiled extremist leaders and terrorists. As of 18 October 2006, Israel has discovered 20 tunnels used for illegal arms smuggling under the border of the Gaza Strip and Egypt. Israel had said it would withdraw from the Strip and end the operation as soon as Shalit was released. The Palestinians had said that they were willing to return Shalit in exchange for the release of some of the Palestinians held in Israeli jails. The Palestinians and others have also said the assault was aimed at toppling the democratically elected Hamas-led government and at destabilizing the Palestinian National Authority, citing the targeting of civilian infrastructure such as a power station and the captures of government and parliament members. Some 300 Palestinians had been targeted by the IDF in the Gaza Strip since the kidnapping of Corporal Gilad Shalit. In July 2006, first reports emerged about mystery injuries after Israeli attacks. Previously unseen injuries included severely damaged internal organs, severe internal burning and deep internal wounds often resulting in amputations or death. Bodies arrived severely fragmented, melted and disfigured. There were speculations about a new experimental weapon, particularly Dense Inert Metal Explosives (DIMEs). Attempting to curb Qassam rocket attacks fired at Southern Israel by Palestinian militants from the northern Gaza Strip, Israel launched Operation "Autumn Clouds" on 1 November 2006. On 8 November 2006, a day after Israel's withdrawal following Operation "Autumn Clouds," Israel Defense Forces shells missed their target—possibly due to a "technical malfunction"—and hit a row of houses in the Gaza Strip town of Beit Hanoun, killing 19 Palestinians and wounding more than 40. Israeli Defense Forces launched an investigation into the Beit Hanoun November 2006 incident (and later apologized for the incident), and the then Israeli President Ehud Olmert offered humanitarian assistance to those affected. The 2006 Franco–Italian–Spanish Middle East Peace Plan was proposed after Israel invaded the Gaza Strip in Operation "Autumn Clouds" by Spanish Premier José Luis Rodríguez Zapatero during talks with French president Jacques Chirac.