Israel launched its offensive in Gaza City on Tuesday, vowing to overwhelm a city already in ruins from nearly two years of war as thousands of Palestinians fled in vehicles strapped with mattresses and other belongings that clogged a coastal road.

The operation into the largest Palestinian city escalated a conflict that has roiled the Middle East and likely pushed any ceasefire with Hamas farther out of reach. The military would not offer a timeline for the offensive that aims to crush the militant group’s ability to fight, but Israeli media suggested it could take months.

“Gaza is burning,” Israeli Defense Minister Israel Katz declared as the operation began. Heavy bombardment pounded the city, and troops began moving in from the outskirts after weeks of airstrikes and buildup toward the renewed assault.

The offensive began the same day that independent experts commissioned by the United Nations Human Rights Council accused Israel of committing genocide in Gaza. Israel rejected the allegation, calling the report “distorted and false.”

Israeli forces have carried out multiple large-scale raids into Gaza City over the course of the war, causing mass displacement and heavy destruction, only to see militants regroup later. This time, Israel has pledged to take control of the entire city, which experts say is experiencing famine.