U.S. President Joe Biden on Saturday held separate phone calls with Israeli Prime Minister Benjamin Netanyahu and Palestinian President Mahmoud Abbas and expressed concerns about the escalating Israel-Hamas conflict in the region, voicing support for the two-state solution.

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Building used by international media in Gaza destroyed by airstrike

In his first phone conversation with Abbas since taking office, Biden "stressed the need for Hamas to cease firing rockets into Israel." The two leaders "expressed their shared concern that innocent civilians, including children, have tragically lost their lives amidst the ongoing violence," a readout released by the White House said.

Conveying the "U.S. commitment to strengthening the U.S.-Palestinian partnership," Biden highlighted his administration's recent decision to restore aid to the Israeli-occupied West Bank and Gaza that had been cut under former President Donald Trump.

The U.S. president also "shared his grave concern over the intercommunal violence across Israel" in his phone conversation with Netanyahu, talking about "the safety and security of journalists and reinforced the need to ensure their protection."

Meanwhile, Biden "reaffirmed his strong support for Israel's right to defend itself against rocket attacks from Hamas and other terrorist groups in Gaza," said the readout. 

Envoys from the U.S., UN and Egypt were working to restore calm as both Israel and Hamas have insisted they would continue their cross-border fire. The UN Security Council was due to meet later on Sunday to discuss the worst outbreak of Israeli-Palestinian violence in years.

At least 148 have been killed in Gaza since the violence began on Monday, including 41 children, reported Reuters citing health officials in Gaza. 

Militant groups in Gaza continued firing barrages of rockets targeting cities in northern, central and southern Israel. More than 200 rockets were fired from Gaza at Israel in the last 12 hours, reported Xinhua citing a spokesperson of the Israeli army. Israel has reported 10 dead, including two children.

Israel bombed the home of Hamas's chief in Gaza early on Sunday and the Islamist group fired rocket barrages at Tel Aviv.

Israeli fighter jets on Saturday bombed and demolished Jala Tower, a high-rise building in Gaza City housing Al-Jazeera TV and Associated Press (AP) offices as well as residential apartments.

The building "contained military assets belonging to the intelligence offices of Hamas," said an Israeli military spokesperson in a statement.

AP President and CEO Gary Pruitt said in a statement that "we are shocked and horrified that the Israeli military would target and destroy the building housing AP's bureau and other news organizations in Gaza."