Israeli aircraft struck terrorist targets in crowded areas in the Gaza Strip and killed a senior Islamic Jihad leader with a missile strike on a media center Monday, driving the Palestinian death toll over 100.

Broadening its campaign in the 6-day-old offensive aimed at quelling Hamas rocket fire on southern Israel, the IAF attacked homes of activists in Hamas, the Islamic terrorist group ruling the Gaza Strip. Among the targets were two buildings in the northern and central Gaza Strip belonging to senior Hamas leaders being used as command and control centers, military sources said.

Israeli Air Force strikes in the southern Gaza Strip also targeted over 50 smuggling tunnels. The IDF Spokesman said “hundreds” of rocket launch sites had been hit, and that while dozens of rockets continued to pound Israel, Hamas’s capacity was being steadily weakened.

The attacks led to a spike in civilian casualties, with 24 civilians killed Sunday and Monday, a Gaza health official said.

Egyptian-led efforts to mediate a cease-fire between Israel and Hamas got into gear. While Israel and Hamas were far apart in their demands, both sides said they were open to a diplomatic solution — and prepared for further escalation if that failed.

The leader of Hamas took a tough stance, rejecting Israel’s demands that the terror group stop its rocket fire. Instead, Khaled Mashaal said, Israel must meet Hamas’s demands for a lifting of the blockade of Gaza.

“We don’t accept Israeli conditions because it is the aggressor,” he told reporters in Egypt. “We want a cease-fire along with meeting our demands.”

An Israeli official said Israel hoped to find a diplomatic solution to the crisis as well and signaled Egypt was likely to play a key role in enforcing any truce.

“We prefer the diplomatic solution if it’s possible. If we see it’s not going to bear fruit, we can escalate,” he said.

The official said Israel doesn’t want a “quick fix” that will result in renewed fighting months down the road. Instead, Israel wants “international guarantees” that Hamas will not rearm or use Egypt’s neighboring Sinai peninsula for terrorist activity.

Overall, the offensive that began Wednesday killed 105 Palestinians, including 53 civilians, and wounded 840 people, including 225 children, Gaza heath official Ashraf al-Kidra said.

On the Israeli side, three civilians have died from Palestinian rocket fire and dozens have been wounded.

Hamas and other terrorist organizations have fired at least 1,150 rockets at Israel since Operation Pillar of Defense began on Wednesday, 135 of them on Monday. The Iron Dome missile battery has intercepted 347 incoming rockets, 42 on Monday, and 664 have hit southern Israel, among them two that hit two empty schools in the coastal city of Ashkelon Monday. Surveying the smashed facilities, police said they shuddered to think of the likely consequences had the schools been functioning as usual.

Schools in southern Israel have been closed since the start of the offensive on Wednesday, and large police units deployed in the area to respond to any potential damage and injuries from rockets.

A poll published in the Haaretz daily on Monday showed widespread support in Israel for the offensive. It said that 84 percent of the public supports the operation, with 12 percent opposed. At the same time, it said just 30 percent of the public supports a ground invasion of Gaza. The poll, conducted by the Dialog agency, surveyed 520 people and had a margin of error of 4.4 percentage points.

West Bank Palestinians demonstrated Monday against Israel’s actions, confronting IDF troops in a major upsurge in violent protest. One Palestinian was shot dead by the IDF when he attacked a soldier in the Hebron hills area; another Palestinian who was shot at a protest earlier in the week in Nabi Saleh died of his wounds. Palestinians reported more than 50 people were hurt.

In Monday’s violence, an Israeli airstrike on a high-rise building in Gaza City killed Ramez Harb, a senior figure in Islamic Jihad’s military wing, the Al Quds Brigades, the group said in a text message to reporters. A number of foreign and local news organizations have offices in the building, which was also struck on Sunday. A passer-by was also killed, medics said.

Thick black smoke rose from the building. Paramedics said several people were wounded.

Islamic Jihad, a smaller sister group to Hamas, said it believed Harb was the target of the strike.

Israel has killed dozens of wanted militants in surgical strikes throughout the operation, the result, officials say, of intelligence gathered from its collection of high-flying drones overhead and a network of informants.

In Gaza City, the patriarch of the Dalu family, Jamal, sat in mourning for 11 members of his family killed in a missile strike on his home Sunday. Among the dead were his wife, his son, daughter-in-law, his sister and four grandchildren. He embraced relatives and neighbors paying their condolences, his face swollen from crying. He disputed Israel’s initial claim that a senior Islamic Jihad operative was hiding in his house.

The IDF said its initial probe of the incident showed that rocket command chief Yihya Abiya had been hit in the strike, and that it had not been aware there were many civilians in the immediate vicinity.

Egypt was trying to broker a cease-fire with the help of Turkey and Qatar. Turkish Foreign Minister Ahmet Davutoglu and a delegation of Arab foreign ministers were expected in Gaza on Tuesday.

A senior Egyptian official told The Associated Press that Hamas and Israel were each presenting Egypt with their conditions for a cease-fire.

“I hope that by the end of the day we will receive a final signal of what can be achieved,” said the official. He said Israel and Hamas are both looking for guarantees to ensure a long-term stop to hostilities. The official says Egypt’s aim is to stop the fighting and “find a direct way to lift the siege of Gaza.”

UN Security General Ban Ki-moon also arrived in Cairo to appeal for an end to violence.

But Mashaal said Gazans were prepared to keep fighting.

“Gaza’s demand is not a halt to war. Its demand is for its legitimate rights,” including a stop to Israeli attacks, assassinations and a lifting of the blockade, Mashaal said.

Israel has been jittery that a second front along its northern border could be opened, either by militants in Lebanon or from spillover from the Syrian civil war.

Lebanese military experts dismantled two Katyusha rockets Monday that were equipped with timers and ready to fire at Israel, a senior Lebanese security official said.