Israeli Energy Minister Israel Katz said Monday that he had instructed authorities to cut water supply to the Gaza Strip.
"All the water supply pipes from Israel to the Gaza Strip have been disconnected," Israel's Channel 12 quoted Katz as saying.
He said electricity and fuel supplies were cut off from Gaza two days ago.
The latest move comes after Israeli Defense Minister Yoav Gallant decided Monday to impose a "complete" siege on Gaza, saying no electricity, food, water or fuel will reach the Gaza Strip.
Since Saturday, Israel has closed all crossings with the Gaza Strip in both directions.
The Gaza-based Palestinian resistance group Hamas launched Operation Al-Aqsa Flood against Israel early Saturday, firing a barrage of rockets. It said the surprise attack was in response to the storming of Al-Aqsa Mosque in occupied East Jerusalem and growing settler violence.
In retaliation, the Israeli army launched Operation Swords of Iron against Hamas in the Gaza Strip.
The number of Palestinians killed by Israeli forces in Gaza has risen to 704, including 143 children and 105 women, the Gaza-based Health Ministry said early Tuesday.
It said the number of wounded has risen to around 4,000.
At least 900 Israelis have been killed and over 2,600 others wounded in the fighting, according to the Israeli Health Ministry.
