The head of Iran's Revolutionary Guards said Saturday that the Palestinians are "not alone" in their fight against Israel as they faced a second day of air strikes in Gaza.

"Today, all the anti-Zionist jihadi capabilities are on the scene in a united formation working to liberate Jerusalem and uphold the rights of the Palestinian people," Major General Hossein Salami said in a statement on the Guards' Sepah News website.

"We are with you on this path until the end, and let Palestine and the Palestinians know that they are not alone," he told the visiting leader of Palestinian militant group Islamic Jihad, Ziad al-Nakhala, during a meeting in Tehran.

Israel has said it launched a "pre-emptive" operation against Islamic Jihad on Friday to avert an imminent attack following days of tensions along the Gaza border.

The Gaza health ministry said a five-year-old girl was among 12 people killed by the Israeli bombardment. More than 80 others have been wounded.

Iran's foreign ministry condemned Israel's "brutal attack" on Gaza.

President Ebrahim Raisi said Israel has "once again showed its occupying and aggressive nature to the world," according to a statement from his office.