Israeli warplanes and artillery attacked the northern Gaza Strip on Sunday and Palestinian medics said eight people were killed shortly after Israel and Hamas missed a deadline for a ceasefire that could pave the way for halting the Middle East's most devastating conflict in years.

The delay in implementing the ceasefire and the latest violence came after Israeli Prime Minister Benjamin Netanyahu asked, an hour before the 8:30 a.m. deadline, that Hamas provide the names of three hostages it was to release on Sunday as part of the agreement.

Hamas had said it was committed to the ceasefire but that it had been unable so far to provide the hostage list for "technical field reasons," without elaborating.