Israeli aircraft have struck 30 houses in the Gaza Strip, killing a leader of the militant Islamic Jihad group and two of his sons.
Israeli ground troops and Hamas gunmen fought intense battles in the north and centre of the territory, Palestinian officials said.
The Israeli military said it hit 45 sites in Gaza, including what it said was a Hamas military command post, while Gaza militants continued to fire dozens of rockets at Israel, with one hitting an empty house.
On the 18th day of fighting, Israel's security cabinet is to convene later today to consider international ceasefire proposals, an Israeli defence official said.
One plan calls for a five-day humanitarian truce during which Israel and Hamas would negotiate new border arrangements for blockaded Gaza, said Hana Amireh, a senior Palestine Liberation Organisation official in the West Bank, who is involved in ceasefire efforts.
Hamas has said it will not halt fire without international guarantees that Egypt and Israel will open Gaza's border crossings and end their seven-year-old blockade. Israel and Egypt are reluctant to ease the blockade, fearing this will enable Hamas to tighten its grip on Gaza.
Israeli government spokesman Mark Regev said Hamas chief Khaled Mashaal has "put so many preconditions on a ceasefire so as to make it impossible".
Israeli media reported that the military also wants more time to continue destroying rocket sites and tunnels from Gaza into Israel, which Hamas has used to launch attacks.
The military says it has found 31 tunnels but only destroyed about a third of them so far. Israel has mobilised more than 65,000 reserve forces during the fighting.
In Jerusalem, hundreds of Palestinians protested in the traditionally Arab east of the city after Muslim noon prayers, and a dozen protesters threw rocks and fireworks at Israeli police, who fired stun grenades and water cannons. Thousands of Israeli security forces had been deployed for possible Palestinian protests.
The night before, thousands of Palestinians protesting against the Gaza fighting clashed with Israeli security forces in the West Bank and in East Jerusalem in one of the biggest protests in the territory in years. One Palestinian was killed and dozens were wounded, according to Palestinian medical officials.
In Gaza, the Palestinian death toll reached 828, after 115 were killed on yesterday in one of the deadliest days of fighting, said Ashraf al-Kidra, a Palestinian health official. More than 5,200 Palestinians have been wounded since July 8, he said.
During the same period, 35 Israelis, among them 33 soldiers, and a Thai worker were killed. Included in the count is an Israeli reservist killed today, the army said.
Early today, Israeli warplanes struck 30 houses throughout the Gaza Strip, including the home of Salah Hassanein, a leader of the military wing of Islamic Jihad, the second-largest militant group in Gaza after Hamas.
Hassanein and two of his sons were killed in the airstrike, said Gaza police spokesman Ayman Batniji and al-Kidra. The Israeli army confirmed the strike.
Over the past two weeks, Israeli aircraft have repeatedly hit homes of Hamas and Islamic Jihad leaders. Most had gone into hiding, but the strikes killed a leader of an Islamic Jihad rocket squad, a Hamas commander and a son of senior Hamas leader Khalil al-Haya, according to the Israeli military.
Such strikes have also claimed the lives of a large number of civilians. A Gaza human rights group said earlier this week that close to 500 homes have been damaged or destroyed in direct hits from the air, and that more than 320 people have been killed in their homes as a result of military strikes.
Germany's two largest airlines said they are not yet resuming flights to Israel even though the European Aviation Safety Agency has lifted a recommendation that airlines refrain from flying to Tel Aviv.
Air Berlin says flights to Tel Aviv remain suspended at least through midday today, while Lufthansa says all today's flights to the airport have been cancelled because of ongoing security concerns after a Gaza rocket landed about a mile away from Israel's international airport.
Lufthansa's cancellations apply to subsidiaries Germanwings, Austrian Airlines, Swiss and Brussels Airlines as well.
Meanwhile, four Palestinians were shot and killed during West Bank protests against Israel's military operation in Gaza, Palestinian hospital officials said.
The circumstances of the shootings in the northern village of Hawara, near the city of Nablus, and the southern village of Beit Omar, near the city of Hebron, were not immediately clear.
Clashes between Israeli troops and protesters were reported in both locations. The Israeli military had no immediate comment.
The West Bank has become increasingly restive over Israel's ground operation in Gaza, in which more than 800 Palestinians were killed and more than 5,200 wounded since July 8, according to Palestinian health officials.
Yesterday, thousands of Palestinians clashes with Israeli forces at a West Bank checkpoint and in East Jerusalem, the largest protests in those areas in several years.
On Friday, two Palestinians, ages 21 and 22, were shot and killed during a protest in Hawara, said Mazen al-Hammouz, director of Rafidiyeh Hospital in Nablus.
In Beit Omar, protesters threw stones at Israeli soldiers posted at the entrance to the village, according to local journalists. The emergency room at Hebron hospital said two men, ages 47 and 27, were killed by gunfire.