On May 11th, an armored personel carrier was destroyed and six IDF troops were killed during an incursion by the Israeli military into the Gaza City neighborhood of Zeitoun. The Israeli army sent in more troops and on May 12th a second military transport vehicle was destroyed killing five more IDF soldiers and on May 14th two more IDF troops were killed by Palestinian snipers. The deaths of 13 IDF soldiers in less than a week marked the largest number of Israeli military personel killed in conflict with Palestinians in several years. Some commentators think that this could indicate a shift in tactics for Palestinian militants from "isolated bombings and incidents to systematic and coordinated guerrilla warfare throughout the Gaza Strip"
Eyeless in Gaza | Israel storms Gaza for troops' remains