TEL AVIV — Israel has appealed the arrest warrants the International Criminal Court issued for Prime Minister Benjamin Netanyahu and former Defense Minister Yoav Gallant as the official death toll in Gaza nears 45,000, according to Palestinian health authorities.

The enclave was pushed closer to the grim milestone by Israeli airstrikes that killed at least 26 people Sunday, including 16 at a school sheltering displaced Palestinians in northern Gaza.

Oren Marmorstein, a spokesperson for…