Israel is currently conducting “wide-scale strikes” on several Hamas “strategic” centres in Gaza, according to Israel Defence Forces IDF.

The IDF confirmed in a statement Monday, that Israeli forces are currently conducting “wide-scale strikes” on several “strategic” centres in Gaza belonging to Hamas, adding that more details will follow.

Meanwhile, a father has said he was on the phone with his daughter as she was killed by Hamas gunfire.

Ilan Troen told “CNN this morning” Monday that he was on the phone with his daughter, Deborah Matias, at the moment she was killed shielding her 16-year-old son from Hamas gunfire this weekend.

“We were on the phone with Deborah as she was killed,” said Troen, a professor emeritus at Brandeis University, said. Troen’s son-in-law, Schlomi Matias, was also killed, he said while speaking to CNN from Be’er Sheva, Israel.

“We were on the phone the entire day with our grandson, Rotem, as he lay first under her body, and then found a place to escape under a blanket in a laundry,” he added, later clarifying that a group text message was used to communicate with his grandson, who was injured but will survive.

“He was told not to speak and therefore he was to hide and use texting,” Troen said. “By the time he was rescued, he had four per cent left in his battery.”

“The brunt of the shot was borne by his mother,” Troen said, remembering his late daughter as a “child of light and life.”

“She, rather than becoming a scientist or a physician, she said to me one day, ‘Dad, I have to do music, because it’s in my soul,'” Troen said. His daughter attended the Berkeley College of Music in Boston, as well as the Rimon School of Music in Tel Aviv, where she met her husband.

It is unclear whether members of Troen’s family had US citizenship.

Israel had earlier in the day announced that it had gone into full –blown war with Hamas after Saturday’s unprecedented attacks, which left over 700 Israelis dead.

Israel’s military had confirmed that it has retaken control of all communities around Gaza, more than 48 hours after Hamas launched a surprise assault in which more than 700 people were killed.

Videos show the horror on the ground, including an attack on a music festival where Israeli rescuers say they found 260 people dead.

Other clips show Israeli civilians being captured. Hamas claims it is holding more than 100 hostages, including Israeli army officers.

Israel’s Minister of Defense said he has ordered the “complete siege” of Gaza, cutting off electricity, food, fuel and water to the enclave.

This comes as Israel has pounded Gaza with airstrikes and formally declared war on Hamas Sunday. More than 550 Palestinians have died, according to Gaza’s health ministry, and medical care has been complicated by Israel cutting power to the territory.

At least nine US citizens are among those who have died after Hamas’ attack on Israel, a US National Security Council spokesperson said Monday.