Palestinians in northern Gaza reported fierce air and artillery strikes early Monday as Israeli troops backed by tanks pressed into the enclave with a ground assault that drew increased international calls for the protection of civilians.

Israeli airstrikes hit areas near Gaza City's Shifa and al-Quds hospitals, and Palestinian militants clashed with Israeli forces in a border area east of the city of Khan Younis, in the enclave's south, Palestinian media reported.

There was no comment from Hamas or the Israeli military on the fighting early Monday. Journalists were not able to confirm the reports.