Israeli warplanes carried out airstrikes in the Gaza Strip early Tuesday, while Israel's military reported continued rocket fire from the Palestinian territory.
The violence that sparked Monday with a rocket attack from Gaza that wounded seven people in a house north of Tel Aviv stretched into a second day despite an announcement by Palestinian officials of an Egyptian-mediated cease-fire.
Monday evening Israeli airstrikes hit dozens of targets across the Gaza Strip, including the office of the leader of the militant group Hamas.
There were no immediate reports of casualties from the airstrikes.
Israeli Prime Minister Benjamin Netanyahu was visiting Washington at the time of the Hamas attack. He said during a meeting with U.S. President Donald Trump, 'Israel will not tolerate this. I will not tolerate this.'
He said Israel 'will do whatever we must do to defend our people and defend our state.'
The rocket attack was the second launched toward central Israel in recent weeks, and prompted Netanyahu to cut short his trip to Washington.
U.N. Secretary-General Antonio Guterres said Monday he was 'gravely concerned by the latest developments' in the Gaza Strip. He called the Hamas rocket attack 'a serious and unacceptable violation' and urged all sides 'to exercise maximum restraint.'
The violence has raised fears of the possibility of a larger conflict just two weeks before elections in Israel.
Margaret Besheer at the United Nations contributed to this report.