Several rockets fired from the Gaza Strip targeted Tel Aviv and southern Israel as the country rang in the New Year on Monday, according to AFP journalists on the ground.
Air-raid sirens sounded as journalists in Tel Aviv saw Israeli missile defence systems intercept the rockets.
People who had gathered on the streets to celebrate New Year's Eve took shelter, while others continued to party.
The attack on southern Israel came at midnight (22:00 GMT) and another targeting Tel Aviv occurred a minute later, according to AFP journalists.
"I was terrified, like it was the first time I saw missiles, its terrifying," Gabriel Zemelman told AFP outside a Tel Aviv bar where he had come to celebrate with friends.
Hamas's military wing, the Ezzedine al-Qassam Brigades, claimed responsibility for both attacks in a video posted on social media.
They said they used M90 rockets in "response to the massacres of civilians" perpetrated by Israel.
The Israeli military confirmed the attack.
Hamas "decided to start 2024 by launching a barrage of rockets at Israel", the military said in a post on social media.
The latest rocket attacks came as Israel continues its bombardment of the Gaza Strip, which has killed at least 21,822 people, mostly women and children, according to the Hamas-run health ministry.
The war was triggered by an unprecedented Hamas attack on southern Israel on 7 October, which left around 1,140 people dead, most of them civilians, according to an AFP count based on official Israeli data.