 Meanwhile, because Hamas refused to recognize Israel's right to exist or reaffirm its commitment to previous agreements between the Palestinian Authority and Israel, the Israeli government and the Quartet (the EU, the UK, the US and Russia) imposed an economic embargo on the Hamas government.Early this morning, July 29, 2006, the IDF began engineering work in the Erez industrial area in the northern Gaza Strip in order to thwart terror threats and to discover tunnels and explosive devices in area.In addition, the IDF carried out aerial attacks against a structure used by Hamas to store and manufacture weaponry in Gaza City, as well as a tunnel located along the Israeli-Egyptian border near Rafah in the southern Gaza Strip.