The death toll continues to mount after terrorist group Hamas launched a surprise attack on Israel.
The attack has been the deadliest ever for Israel.
According to various reports, over 600 Israelis and around 370 in Gaza have been killed aftermath of the Hamas attack.
Reuters quoting Israel's main military spokesman called the attack by Hamas, who killed at least 700 Israelis and abducted dozens, as "the worst massacre of innocent civilians in Israel's history" and the response has been correspondingly harsh.
Israel Prime Minister Benjamin Netanyahu has pledged to reduce Hamas' hideouts in Gaza to rubble in response to the attack.
The Palestinian death count in Gaza climbed to nearly 300 as a result of intense air strikes on the coastal enclave, Reuters reported.
The report also said throughout the night, intense gun battles ensued between Israeli forces and hundreds of Hamas fighters across at least 22 locations in Israel.
The report also added this included at least two areas where gunmen were holding hostages.
Meanwhile, Hamas has said that the United States' plan to provide increased military aid to Israel amounts to "aggression" against Palestinians, after Washington ordered navy ships and warplanes closer to Israel.
"The announcement of the US that it will provide an aircraft carrier to support the occupation (Israel) is actual participation in the aggression against our people," said Hamas.
Gaza Suffers Deadliest Attack in 15 Years:
The Gaza Strip has suffered its deadliest day in 15 years in the wake of the unprecedented attack by Hamas into Israel.
The report among the killed in Gaza include three-month-old twins along with their mother and three sisters in an air strike on Saturday in Khan Younis in the southern Gaza Strip.
The report said at least 10 people were killed in that strike, which destroyed four houses.
It added rescuers were still trying to find survivors in the rubble on Sunday.
The Health Ministry in the Hamas-controlled Gaza Strip has reported 370 Palestinians killed so far, and another 2,200 wounded, with nearly 300 killed on Saturday, the largest number of Palestinians killed in Gaza by Israeli attacks in a single day since 2008.
Israeli air strikes on Gaza began soon after the Hamas attack and continued overnight and into Sunday, destroying the group's offices and training camps, along with houses and other buildings, it said.
The report quoting Israeli army said its fighter jets have destroyed 800 terrorist targets so far in the Gaza Strip.
In Rafah city, adjacent to the Egyptian border, an Israeli air strike killed 12 members of the Abu Qouta family, it said.
Home to some 2 million people, the Gaza Strip has been run by Hamas since it seized control of the territory in 2007. Its economy has long been choked by a blockade imposed by Israel with Egypt's help.
As air strikes began on Saturday, thousands of Palestinians living near the frontier with Israel fled their homes.
UNRWA, the UN agency that provides essential services to Palestinians, said at least 20,000 Palestinians were taking shelter at 44 of the schools it operates in the Gaza Strip.