Concerns over a possible ground operation are mounting after a 24-hour evacuation period that Israel had issued to the residents of the Gaza Strip has ended.

The fighting between Israel and the Palestinian militant group Hamas entered its eighth day on Saturday. It has left more than 3,200 people dead, including 1,900 in Gaza and at least 1,300 on the Israeli side.

The Israeli military on Thursday notified the United Nations that residents of the northern Gaza Strip should evacuate to the region's southern area within 24 hours, or by the end of Friday, local time.

But footage has shown continuing attacks in the area with frequent sounds of explosions presumably due to Israeli airstrikes, which occasionally cause blazes.

Hamas has been responding to Israel's evacuation notice with violence. It declared on Friday that it had launched rocket attacks on an Israeli air base and its largest commercial city of Tel Aviv.

Israeli Prime Minister Benjamin Netanyahu said this is just the beginning and the country's forces will destroy Hamas. Israel is seen to be preparing for a large-scale military operation including a ground offensive.

About 1.1 million residents of Gaza have been told to evacuate. UN Secretary-General Antonio Guterres posted a comment on social media on Friday. He said, "Moving more than one million people across a densely populated warzone to a place with no food, water, or accommodation, when the entire territory of Gaza is under siege, is extremely dangerous -- and in some cases, simply not possible."