Local residents and eyewitnesses say dozens of Israeli tanks and military vehicles have pushed into a major residential district of Gaza City, on the second day of Israel's ground offensive aimed at occupying the area.

Video footage shows tanks, bulldozers and armored personnel carriers moving on the edges of Sheikh Radwan in northern Gaza City. Thick clouds of smoke can be seen as Israeli forces fire artillery shells and smoke bombs to cover their advance.

The Sheikh Radwan district was home to tens of thousands of people before the war and is considered one of the city's most densely populated areas.

Israel says the aim of its Gaza City offensive is to free hostages held by Hamas and defeat up to 3,000 fighters in what it describes as the group's last stronghold - but the operation has drawn widespread international condemnation.

The leaders of more than 20 major aid agencies, including Save the Children and Oxfam, warned that the inhumanity of the situation in Gaza is unconscionable.

Residents in Sheikh Radwan said the incursion followed a wave of heavy airstrikes targeting buildings and main streets across the neighborhood, in what appeared to be preparation for the ground assault.

Saad Hamada, a local resident who fled south with his family earlier on Wednesday, told the BBC: The drones didn't leave anything. They hit solar panels, power generators, water tanks, even the internet network.

Life became impossible, and that is what forced most people to leave despite the danger.

Sheikh Radwan includes several key areas and is critical for access across northern Gaza City. The images of tanks in its streets have stoked panic among residents, particularly those still living in western and central sectors of the city, who recall past military incursions that led to devastating destruction.

The operations have triggered a new wave of displacement, with reports of long lines of vehicles and carts piled high with belongings as families evacuate. Many have described the perilous journey south as prolonged and costly, with a lack of adequate transport and soaring expenses.

The Israeli Defense Forces (IDF) confirmed that they are executing extensive airstrikes while utilizing modified military vehicles and drones in the campaign. Despite ongoing military directives for evacuation, the crowded conditions in southern Gaza add another layer of crisis for the displaced populations.

The UN has raised alarms over the humanitarian crisis as reports indicate significant casualties among Gaza's civilian population since the onset of hostilities, emphasizing the catastrophic potential of the ongoing sanctions and military actions.