The Palestinian Ministry of Health in Gaza has said an Israeli missile caused the fatalities, striking a home belonging to a family in the city of Khan Yunis, the International Middle East Media Center reported on Friday.
The ministry said the projectile also wounded more than 10 Palestinians.
Nine others were also killed earlier when an Israeli warplane attacked a house in the al-Nuseirat refugee camp, near the central city of Deir al-Balah.
Rescue workers also found another body at the site of Israels recent strike in Shejaiya neighborhood.
Israel has been targeting the Gaza Strip with military attacks since July 8. The air, sea and land strikes by Israel have so far killed at least 1,458 people and injured over 8,300 others.
This is Israels third major offensive against the densely-populated Gaza Strip over the past six years.
Israel and the Palestinian resistance movement of Hamas have agreed to an unconditional 72-hour humanitarian ceasefire starting from 08:00 local time Friday, with talks on a permanent truce set to begin in Cairo.
Palestinian casualty figures early Friday indicated that the current conflict had become the deadliest fighting in the Palestinian territories since 1967.
The year saw Israel occupying the Palestinian territories of East al-Quds (Jerusalem), the Gaza Strip, and the West Bank during the Six-Day War. The Tel Aviv regime withdrew from Gaza in 2005, but Israeli forces have been carrying out regular deadly forays into the sliver ever since the pullout.