The Lebanese Hezbollah group launched missiles with heavy warheads at towns in northern Israel, saying it used the weapons against civilian targets for the first time on Thursday in response to Israeli air raids the previous night that killed nine people, including what the group said were several paramedics.

Local media reported no Israeli casualties in the rocket attack. The Israeli military did not immediately comment on the rocket attack.

Since the outbreak of the war between Israel and Hamas in Gaza on October 7, fears have grown that the near-daily clashes along the Israel-Lebanon border could escalate into a full-scale war. The air raids and rocket launches on Wednesday killed 16 Lebanese and one Israeli, making it the deadliest day in the current conflict.

Senior Israeli military spokesman Admiral Daniel Hagari said Israel killed 30 Hezbollah fighters last week and destroyed dozens of Hezbollah military sites in an attempt to keep the Iran-backed group away from the border.

The recent surge in violence has raised alarms in Washington and at the United Nations.

White House National Security spokesperson John Kirby told reporters: "Restoring calm along that border remains a top priority for President Biden and the administration," adding that the United States is closely monitoring developments. "We have also been very clear: we do not support war in Lebanon.”

Kirby said the United States is working to stop the fighting through diplomatic efforts. He said this should be a top priority for Israel and Lebanon, and would allow displaced civilians to return home. Tens of thousands of people on both sides have fled the fighting.

A Hezbollah statement said that at sunset on Thursday, a barrage of Katyusha and Volcano rockets was launched toward the Israeli villages of Goren and Shlomi. Hezbollah’s Al-Manar channel said the group had not previously launched Volcano rockets at civilian targets, but is now responding to the recent wave of Israeli air raids.

Official Lebanese media reported that 10 paramedics were among those killed on Wednesday. The Israeli military said it struck Hezbollah targets and a Sunni allied group.

Hezbollah has frequently used Russian-made Kornet anti-tank portable missiles in recent months. On rare occasions, it has launched Volcano rockets, which, according to the group’s leader Hassan Nasrallah, can carry a warhead weighing between 300 kilograms (660 pounds) and 500 kilograms (1100 pounds).

Hezbollah confirmed its attacks aim to keep some Israeli units occupied and away from Gaza, and Nasrallah says attacks on the border will not stop until Israel halts its offensive in Gaza.

General C.Q. Brown, chairman of the U.S. Joint Chiefs of Staff, told reporters on Thursday that he discussed with his Israeli counterparts that Israel does not need "to have a northern front they have to deal with while handling Gaza." He said he also spoke with the Lebanese Defense Minister, trying to do what the United States can "to help bring down the temperature."

The United Nations peacekeeping force in southern Lebanon, known as UNIFIL, said on Thursday that it is essential that “this escalation stops immediately.”

UNIFIL added: “We urge all parties to lay down their arms and start the process toward a sustainable political and diplomatic solution,” confirming that the peacekeeping force remains ready to support this process in any possible way.

The fighting has killed nine civilians and 11 soldiers in Israel. More than 240 Hezbollah fighters and about 50 civilians have been killed in Lebanon.