Four Israeli soldiers have been killed and five others injured in an explosion in a building in Rafah in the southern Gaza Strip, the army said on Wednesday. Three of the injured were in critical condition and receiving treatment at hospital. The Israeli news site Ynet reported that an explosion occurred while the soldiers were searching a building in Rafah for weapons and ammunition. A 20-year-old military medic who died is the first female soldier to have been killed during Israel’s 11-month-old ground offensive against Hamas and other extremists in the Gaza Strip, Ynet said.