Israel’s overnight air strikes hit Gaza’s security headquarters and police stations, in the heaviest bombardment since operations began on July 8.
Israel also said its troops had carried out a brief raid against a rocket-launching site in the coastal territory.
It added that Palestinian militants fired about 90 rockets from the Gaza Strip into its territory on Saturday.
At least 159 Palestinians have died in the air strikes, Gaza officials say.
They are said to include 17 members of one family who died in an Israeli missile strike on Saturday evening.
Israel says it is targeting Hamas militants and facilities, including the homes of senior operatives. However, the UN has estimated that 77% of the people killed in Gaza have been civilians.
The UN Security Council called for a ceasefire and peace talks on Saturday. It is the first time since Israel’s offensive began that they have issued a statement, with members previously divided on their response.
Early on Sunday, Israeli air strikes destroyed most of the security headquarters and police stations run by Hamas Islamist militants.
The homes adjacent to the security compound suffered extensive damage, as the headquarters are located in the densely populated neighborhood of Tel al-Hawa in south Gaza.
The Israel Defense Forces (IDF) said troops also raided a site used to fire long-range rockets at Israel.
“The mission was accomplished,” the IDF wrote on its official Twitter account.
It added: “During the mission, there was an exchange of fire. Four soldiers were lightly injured and all returned home safely.”
It is believed to be the first time Israeli troops – thought to be naval commandos on this occasion – have entered Gaza since Israel launched Operation Protective Edge, which it says is aimed at stopping rocket attacks and destroying Hamas’ capabilities.
The IDF said it was dropping leaflets over the city of Beit Lahiya in northern Gaza, warning residents to seek shelter from planned air strikes later on Sunday.
“We do not wish to harm civilians in Gaza, but these civilians must know that remaining in close proximity to Hamas terrorists and infrastructures is extremely unsafe,” the IDF said.
The IDF says it has so far struck some 1,320 “terror” sites across Gaza, while Hamas have launched more than 800 rockets at Israel.
Israel’s Iron Dome missile shield intercepted four rockets on Sunday morning above central and southern Israel, Israeli newspaper Haaretz reports.
At least five Israelis have been injured this week by rocket and missile attacks, two of them seriously, but no Israelis have been killed by the attacks.
On Saturday evening, four Israeli missiles hit a three-storey house in Gaza belonging to police chief Tayseer al-Batsh, a Gaza health official said.
The strike killed 17 members of the same family, while Tayseer al-Batsh was wounded but survived, officials added.
A witness said: “We were praying in a mosque adjacent to the targeted house and suddenly we heard a huge explosion followed by another explosion.”
Hamas spokesman Sami Abu Zuhri described the raid as “a heinous crime”, adding: “Israel will pay a heavy price for its aggression against the Palestinian people.”
Palestinian sources say more than 1,000 people have been injured since Israel began its operation six days ago.
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