A Hezbollah drone attack on an army base in central Israel killed four soldiers and severely wounded seven others on Sunday, the Israeli military said, in the deadliest strike by the militant group since Israel launched its ground invasion of Lebanon nearly two weeks ago.

The Lebanon-based Hezbollah called the attack near Binyamina city retaliation for Israeli strikes on Beirut on Thursday that killed 22 people.

It later said it targeted Israel’s elite Golani brigade, launching dozens of missiles to occupy Israeli air defense systems during the assault by “squadrons” of drones.

Israel’s national rescue service said the attack wounded 61.

With Israel’s advanced air-defence systems, it’s rare for so many people to be injured by drones or missiles.

Hezbollah and Israel have traded fire almost daily in the year since the war in Gaza began, and fighting has escalated.

Israel launched its ground operation in Lebanon earlier this month with the goal of weakening Hezbollah and pushing the militant group away from the border to allow thousands of displaced Israelis to return to their homes.

Inside Gaza, an Israeli airstrike killed at least 20 people including children at a school Sunday night, according to two local hospitals.

The school in Nuseirat was sheltering some of the many Palestinians displaced by the war.

Meanwhile, explosions hit early Monday outside Al-Aqsa Martyrs Hospital in Deir al-Balah, killing three people and injuring about 50 others, the hospital said.

Tents caught fire, and residents of the Central Gaza community carried the injured into the hospital.

Hezbollah's deadly strike in Israel came the same day that the United States announced it would send a new air-defence system to Israel to help bolster protection against missiles, along with troops needed to operate it.

An Israeli army spokesperson declined to provide a timeline. (AP)