The sisters of an Israeli woman kidnapped and killed by Hamas have described the “inhuman” conditions in which she was held captive, telling CNN they have been living “a nightmare” since her body was recovered by the Israeli military in an underground tunnel in Gaza.

Palestinian authorities say 15 people were killed overnight in the Gaza Strip in multiple Israeli attacks. An airstrike early Friday morning in Gaza City hit a family home, killing six people including an unknown number of children, Gaza’s Civil Defense said. Another person was killed in Gaza City when a strike hit a group of people on a street.

Khaled Meshal, one of Hamas’s most senior officials, said in an interview that the militant group expects to play a decisive role in the enclave when the war is over.