Israel killed eight Palestinians overnight before a five-hour humanitarian truce came into effect at 10am Thursday.
Shortly before 10am., Israeli artillery shells killed three Palestinians from the Abu Sneima family and injured four others in eastern Rafah.
Gaza health ministry spokesman Ashraf al-Qidra said three bodies, including a woman, were removed from a Rafah home.
Earlier, five Palestinians were killed in Israeli attacks.
Muhammad Hassunah, 65, and Muhammad al-Hoot were killed by an Israeli missile at 4 a.m. while on their way to a mosque in Rafah for dawn prayers.
Zaynab Muhammad al-Abadlah, 71, died Thursday morning from injuries sustained in an Israeli airstrike in Khan Younis and 22-year-old Muhammad Mahmoud al-Qadim died in an air strike on central Gaza.
Also on Thursday morning, a 22-year-old man Muhammad Mahmoud al-Qadim succumbed to wounds he sustained in an Israeli raid in eastern Deir al-Balah in the central Gaza Strip.
Ahmad Rihan, 23, was killed in northern Gaza by an Israeli aerial attack.
Israeli forces bombed the Khalil family home in Gaza City and the house of former Gaza minister of interior Fathi Hammad in Beit Lahiya.
War planes also targeted a building under construction belonging to a charitable society for women in Gaza City.
The Israeli army said it conducted at least 37 raids overnight on Gaza, while seven rockets were fired from the Strip, four of which landed in fields and the rest were intercepted by Israel's missile defenses.
Thirteen Gaza fighters emerged from a tunnel under the southern Gaza border, and were headed towards Sufa kibbutz, a small community just over a kilometer away, when they were spotted, Israeli army spokesman Lieutenant Colonel Peter Lerner told journalists.
Israel forces killed at least one of the militants in an air raid, he said, leaving the rest rushing back towards the tunnel.
The sides announced a temporary lull in fighting after Israel resumed airstrikes following the failure of an Egyptian-brokered truce, which Hamas says was not discussed with the group before being made public.
A senior UN official said that it was unlikely any new aid would reach Gaza.
"The Kerem Shalom crossing is closed today for security reasons, aid can't come through Erez -- it's not big enough -- so no new aid is going to enter Gaza today," the official said, referring respectively to Gaza's southern goods crossing and northern personnel border.
Instead, the truce would allow people who have fled their homes to go back to collect supplies from them, and help the UN get to areas it could not reach before, the official told AFP, speaking on condition of anonymity.

Al Bawaba