Lebanese militant group Hezbollah fired dozens of rockets at Israel on Saturday in retaliation for the targeted killing of a Hamas leader in Beirut this week amid mounting fears of a larger regional war, according to media reports.

Hezbollah said in a statement Saturday that it targeted an Israeli air surveillance base in northern Israel with 62 missiles as an “initial response” to the suspected Israeli strike on January 2 that killed senior Hamas official Saleh al-Arouri in a Hezbollah stronghold in Beirut. The Israeli military said around 40 rockets were fired from Lebanon at its territory.

Hasan Nasrallah, the leader of Hezbollah, the Iran-backed Lebanese militant group, said earlier this week that the killing of al-Arouri will “not go unpunished.”

The escalation comes as U.S. Secretary of State Antony Blinken has embarked on his fourth diplomatic tour of the Middle East as the Israel-Hamas war reaches its three-month mark and amid growing international criticism of Israel’s strategy. Yemen’s Houthi militants have also increased their attacks on cargo ships and fuel tankers in the Red Sea.

Hamas launched a surprise attack on Israel on October 7, killing nearly 1,200 people and taking around 250 hostages, some of whom have been released.

Israel has for the last three months bombed the Hamas-run Gaza Strip, resulting in nearly 23,000 people dying and around 59,000 others being injured, according to the Palestinian enclave’s health authorities.

In another warning, the United Nations’ humanitarian chief Martin Griffiths said on Friday that Gaza has become “uninhabitable” for its nearly 2.3 million inhabitants and repeated that “a public health disaster is unfolding” in the enclave.