The Israeli military says over 100 rockets have been fired into the country from Lebanon, with some landing near the northern city of Haifa.

Israeli first responders say the early morning barrage on Sunday wounded at least three people near Haifa, damaged buildings and set cars on fire.

The barrage came after an Israeli airstrike in Beirut killed at least 37 people, including one of the Lebanese militant group's senior leaders as well as women and children. The militants were already reeling from a sophisticated attack using thousands of explosive personal devices just days earlier.

Israel and Hezbollah have traded fire since the outbreak of the war in Gaza neary a year ago, when the militant group began firing rockets in solidarity with the Palestinians and its fellow Iran-backed ally Hamas.

But tensions have steadily escalated in recent weeks, raising fears of all-out war.