Too many Palestinian civilians have been killed, UN chief Ban Ki-moon said as he urged Israel to scrap plans for a potentially devastating ground offensive.
Repeating his call for a ceasefire, the secretary-general said he "feels a sense of responsibility for the Palestinians who, especially in the Gaza Strip, have long been denied the sense of freedom and dignity that they deserve", according to a statement released on Sunday.
The situation in Gaza, with at least 170 Palestinians killed and no Israeli casualties, "appears to be worsening", Ban said, noting that the UN Security Council's call for a ceasefire had not been respected.
Reiterating his condemnation of the firing of rockets into Israel by the Islamist movement Hamas that rules Gaza, Ban demanded an "immediate cessation of these indecent attacks".
But a "deeply worried" UN chief also stressed that "too many Palestinian civilians have been killed, and any Israeli ground offensive will undoubtedly increase the death toll and exacerbate civilian suffering in the Gaza Strip".
"It is in the interest of both sides that steps toward dangerous escalation be replaced with immediate measures to end the fighting, thus preventing further casualties and greater risks to regional peace and security," the statement added.
"(Ban) demands both sides move in this direction now."
Despite increasing calls for a ceasefire, Israeli Prime Minister Benjamin Netanyahu said the military was hitting Hamas "with growing force", warning there was no end in sight.
On the Palestinian side, president Mahmud Abbas said he would ask Ban to "put the State of Palestine under the UN international protection system" in order to address the violence in Gaza.
