Israel is making sure the world knows that the campaign to end Hamas's brand of terrorism is non-negotiable as the bombardment of Gaza entered a second day on Saturday after a week-long truce collapsed despite international calls for an extension.

Israel Defense Forces spokesperson Lt. Col. Richard Hecht said that since the war against Hamas began, the IDF has kept its focus on two goals — dismantling Hamas and bringing the hostages home.

During the operational pause last week, 105 of the abducted civilians were released from captivity.

Hecht accused Hamas of violating the pause, including by launching rockets toward Israel early Friday morning.

"The message from Hamas is clear. They chose to prioritize attacking Israeli civilians over the welfare of Gazan civilians, who were relying on the increased deliveries of humanitarian aid," Hecht said.

Israel said it resumed its military operations following the violations by Hamas.

"Our mission to dismantle Hamas began before the pause. We temporarily stopped to enable some of our hostages to come home. Now we are continuing with this mission because we can't ask our children to go back to living alongside a murderous terrorist organization," Hecht stressed.

"Our actions are a measured response, defending our nation, bringing home our hostages, and aiming to dismantle the threat posed by Hamas. This hasn't changed and won't change until victory is achieved," he said.

Israeli government spokesman Eylon Levy told reporters: "Having chosen to hold onto our women, Hamas will now take the mother of all thumpings."

Smoke billows again

Late Saturday, clouds of grey smoke from the Israeli strikes hung over Gaza, where the Hamas-run health ministry said nearly 200 people had been killed since the pause in hostilities expired early Friday.

Both sides blamed each other for breaking the truce, with Israel claiming that Hamas had tried to fire a rocket before it ended and that it failed to produce a list of further hostages for release.

As hostilities resumed, Hamas's armed wing received "the order to resume combat" and to "defend the Gaza Strip," according to a source close to the group who asked not to be named because they were not authorized to speak to the media.

International leaders and humanitarian groups condemned the return to the fighting.

"I deeply regret that military operations have started again in Gaza," UN Secretary-General Antonio Guterres said on X, formerly Twitter.

"Today, in a matter of hours, scores were reportedly killed and injured," UN humanitarian chief Martin Griffiths said. "Families were told to evacuate, again. Hopes were dashed."

Wider rift feared

Fears of a wider regional conflict grew after the Syrian defense ministry said Israeli strikes hit Damascus on Saturday, and the militant group Hezbollah said one of its members was killed in an Israeli strike on Lebanon on Friday.

The United States said it is working with regional partners to reach another ceasefire.

"We're going to continue to work with Israel and Egypt and Qatar on efforts to reimplement the pause," US Defense Secretary Lloyd Austin told reporters in California on Friday.

Mediation efforts by Qatar and Egypt are ongoing, said a source briefed on the talks who asked not to be named.

During the unprecedented attack on 7 October, Hamas fighters broke through Gaza's militarized border into Israel, killing about 1,200 people, mostly civilians, and kidnapping around 240, according to Israeli authorities.

Israel vowed to eliminate Hamas in response and unleashed an air and ground campaign that has killed more than 15,000 people, mostly civilians, the Hamas authorities who run Gaza said

But in a diplomatic breakthrough, both sides agreed to a seven-day truce, during which Hamas freed 80 Israeli hostages in exchange for 240 Palestinian prisoners, and more aid entering Gaza.

The week of hostage-prisoner exchanges yielded tearful reunions of Israeli families with their released relatives and jubilation in the streets of the occupied West Bank as Palestinian prisoners walked free from Israeli jails.

Twenty-five other hostages, mostly Thais, including two Filipinos, were also freed under separate arrangements.

The Israeli army said Friday that five more hostages had died, bringing the total number to seven, and 136 were still being held, including 17 women and children.

US Secretary of State Antony Blinken told reporters in Dubai on Friday that the United States remained "intensely focused on getting everyone home, getting hostages back," and "pursuing the process that had worked for seven days" during the truce.