Fierce Israeli tank fire and aerial bombing struck Khan Younis in the Gaza Strip on Friday night, residents said, after nearly 200 people were reported killed in 24 hours in Israel's campaign against Hamas militants.
Planes also carried out a series of air strikes on the Nuseirat camp in central Gaza, according to medics and Palestinian journalists.
Defense Minister Yoav Gallant said troops were reaching Hamas command centres and arms depots. The Israeli military said it had destroyed a tunnel complex in the basement of one of the houses of the Hamas leader for Gaza, Yahya Sinwar, in Gaza City.
Twelve weeks after Hamas militants stormed Israeli towns, killing 1,200 people and seizing 240 hostages, Israeli forces have laid much of the Gaza Strip to waste as it pursues its war aimed at eradicating the Islamist group.
Nearly all of Gaza's 2.3 million people have fled their homes at least once and many are on the move again, often reduced to taking shelter in makeshift tents or huddled under tarpaulins and plastic sheets on open ground.
The narrow coastal strip is just 40 km (25 miles) long, making it one of the most densely populated areas in the world.
Gaza health authorities said 187 Palestinians were confirmed killed in Israeli strikes in the 24-hour period, raising the overall toll to 21,507 – about 1% of Gaza's population. Thousands more bodies are feared to be buried in the ruins of neighbourhoods.
(Inputs from Reuters)
