Barrages of rockets were fired from the blockaded Gaza Strip on Saturday, killing 300 people in Israel and at least 232 in Gaza.
Sirens blared across the country's south and central areas, with Israel authorities urging people to stay near bomb shelters.
The armed wing of the Palestinian terror group Hamas said it was behind the attack, claiming that it launched over 5,000 rockets at its neighbour.
"We decided to put an end to all the crimes of the occupation (Israel), their time for rampaging without being held accountable is over," the group said.
"We announce Operation Al-Aqsa Flood and we fired, in the first strike of 20 minutes, more than 5,000 rockets."
Here are the Highlights on the big story:
At least 250 Israelis with dozens of hostages in by far the deadliest day of violence in Israel since the Yom Kippur war 50 years ago. More than 230 Gazans were also killed when Israel responded with retaliatory strikes.
Meghalaya Chief Minister Conrad K Sangma on Saturday informed that as many as 27 people from the state are stranded in Jerusalem, Israel adding that he is in touch with the Ministry of External Affairs to rescue them.
Several Indian students in Israel have said that they feel nervous and scared in the face of Hamas' terrorist attack on Israel and are in constant touch with the Indian Embassy.
An Indian student in Israel, Goku Manavalan said: "I am very nervous and scared...Thankfully we have shelter and Israeli police forces nearby. So far we are safe...We are in touch with Indian Embassy people, we have a good Indian community around and we are connected..." Read here
A senior White House official said Saturday it was "too early to say" whether Israel's arch foe Iran was "directly involved" in the large-scale attack by Palestinian militant group Hamas.
However, there was "no doubt Hamas is funded, equipped and armed by Iran and others," he added, as the conflict between the two sides escalated to its bloodiest point in decades.
The Israel death count from the Hamas surprise attack Saturday has surged to more than 200, the army said, accusing the Hamas of breaking into homes and "massacring civilians".
Israeli troops were still battling "hundreds" of Palestinian terrorists at 22 locations inside Israel Saturday after they infiltrated from Gaza during a massive dawn rocket barrage, the army said.
"There are still 22 locations where we are engaging with terrorists that came into Israel from the sea, from the land and from the air," army spokesman Richard Hecht told journalists, adding the Hamas attack included a "robust ground invasion".
Israel's ambassador to France admitted on Saturday that his country was not "sufficiently prepared" for the attack launched by Hamas, pointing to a failure of the intelligence services, reported news agency AFP.
Palestinian terror group Hamas launched a massive surprise attack against Israel on Saturday, firing thousands of rockets from Gaza and sending fighters to kill or kidnap people, leaving at least 70 people dead.
"Following this surprise, we were not sufficiently prepared for it, we could even say barely prepared," Ambassador Raphael Morav said in an interview with France's Europe 1 radio.
Joe Biden warns against "any other party hostile to Israel seeking advantage" after Hamas assault, reported news agency AFP.
Lufthansa has decided to stop flights to Israel which was hit by 5,000 rockets fired by Palestinian militant organisation Hamas this morning, the airlines spokesperson said, reported news agency AFP.
The Ministry of External Affairs has set up a helpline for Indians in Israel to reach out on the phone and on email after Palestine's Hamas launched a surprise rocket attack on its neighbour. Indians living in Israel can call on +97235226748 or send an email to cons1.telaviv@mea.gov.in for any kind of support.
Russia has called for an "immediate ceasefire" in Gaza after Israel declared a state of war today as thousands of rockets launched by militant organisation Hamas struck the country.
World leaders have called for end to hostilities and safe passage for civilians amid the "war" between Israel and Hamas, which started after the Palestine militant group launched thousands of rockets into Israel this morning.
Israel has declared a state of war after a fierce rocket attack from the blockaded Gaza strip and an alleged infiltration by Hamas militants.