The Israeli army said Tuesday it had suffered its biggest single-day losses since the start of its ground war in Gaza amid growing pressure on the government to end its brutal onslaught.
The heavy clashes came as a White House official was due in the region for talks aimed at securing more hostage releases, and as US media reported a new Israeli proposal for a deal that would involve a two-month pause in fighting.
Twenty-four soldiers were killed on Monday, with military spokesman Daniel Hagari saying 21 reservists were killed when rocket-propelled grenade fire hit a tank and two buildings they were trying to blow up with mines.
The UN humanitarian agency OCHA said "ground operations, fighting and attacks intensified" around Gaza's main southern city of Khan Younis.
UN agencies and aid groups have also sounded the alarm about the growing threat of disease and famine in Gaza, where 1.7 million people are estimated to have been uprooted.
Israel has carried out a relentless offensive that has killed at least 25,490 people in Gaza, around 70 percent of them women, children and adolescents, according to the health ministry in Gaza.