The families denounced Netanyahu’s plan to expand military operations. Yehuda Cohen, the father of Nimrod Cohen, an Israeli soldier held hostage in Gaza, said from the boat that Netanyahu is prolonging the war to satisfy extremists in his government and to prevent it from collapsing.

An Israeli official said the Security Cabinet would hold a lengthy debate and approve an expanded military plan to conquer all or parts of Gaza not yet under Israeli control.

Israeli Prime Minister Benjamin Netanyahu said the move would “assure our security,” remove Hamas from power, and would enable the transfer of the civilian administration of Gaza to another party.