As airstrikes continued to pound the Gaza Strip on Monday, the Israel Defense Forces (IDF) claimed to have "severely degraded the capabilities" of the Palestinian Hamas militant group.

In a statement, the IDF said that it targeted a structure that housed Hamas operatives and several of the militant group's operational command centres, including a three-floor facility, reports CNN.

According to the IDF, the other targets include a command centre belonging to a senior Hamas naval forces operative named Mahmad Kashta; a Hamas operational asset in a mosque in Jabalia city; and an intelligence and additional asset used by the militant group.

Since Israel declared war on Hamas on Sunday a day after the militant group launched an unprecedented surprise attack on southern Israel, the Jewish state has continued pounding the besieged coastal enclave with airstrikes.

Meanwhile, hundreds of people are still reported missing, while thousands others were injured in the attacks.

In its latest update, the UN Relief and Works Agency (UNRWA) said the violence has displaced 123,000 Palestinians in Gaza with close to 74,000 seeking shelter in schools, "as heavy shelling and airstrikes continue including on civilian areas".

"UNRWA school sheltering displaced families in the Gaza Strip was directly hit today (Sunday). The school, sheltering more than 225 people, was severely damaged. No casualties were recorded among the displaced," the Agency said in a statement late Sunday.