Prime Minister Benjamin Netanyahu on May 19 said Israel’s bombing of Gaza targets aims to deter Hamas but he did not rule out a campaign to “conquer” the enclave’s Islamist rulers.

Deafening air strikes and rocket fire once more shook Gaza in the conflict that has claimed 219 Palestinian lives according to the Gaza health ministry and killed 12 people in Israel according to Israeli police.

While an international diplomatic push aims to end the worst bloodshed in years, Netanyahu issued another tough threat against the armed group that has fired thousands of rockets at Israel since May 10.

“There are only two ways that you can deal with them,” Netanyahu told a group of foreign ambassadors.

“You can either conquer them, and that’s always an open possibility, or you can deter them, and we are engaged right now in forceful deterrence, but I have to say we don’t rule out anything.”

The goal is to “degrade Hamas’ capabilities, their terror capabilities, and degrade their will,” Netanyahu said.

An Israeli military official, speaking on condition of anonymity, however said in a separate briefing that Israel is now assessing at what stage it may stop its military campaign.

“We are looking at when is the right moment for a ceasefire,” said the source.

Israel was evaluating whether its objective of degrading Hamas’ capabilities had been achieved, the military source said, and “whether Hamas understands the message” that its rocket barrages towards Israel cannot recur.

Israel’s bombing campaign has also left Gaza’s two million population desperate for relief.

Hospitals have been overwhelmed by patients, there are frequent blackouts and sewage from broken pipes has flooded some areas.

Some 72,000 civilians have fled their homes, seeking refuge in UN-run schools and other public buildings, the UN says.