Lebanon's Hezbollah fired big barrages of rockets at Israel on Wednesday in retaliation for an Israeli strike which killed a senior Hezbollah field commander, escalating the conflict across the Lebanese-Israeli border.

The Israeli military confirmed it had killed senior Hezbollah commander Taleb Abdallah as well as three other Hezbollah fighters in a strike on a command and control center in southeastern Lebanon.

The Iran-backed Hezbollah and Israel have been trading fire since the eruption of the Gaza war in October, in steadily intensifying hostilities that have fueled concern of a bigger confrontation between the heavily armed adversaries.

The Israeli strike in south Lebanon village of Jouaiyya late Tuesday killed three Hezbollah fighters alongside the senior field commander identified by Hezbollah as Taleb Abdallah, also known as Abu Taleb, three security sources said.

He was the most senior Hezbollah commander killed during eight months of hostilities, one of the sources said.

The sources said he was Hezbollah's commander for the central region of the southern border strip. His funeral is due to be held later Wednesday.

A security source in Lebanon said Hezbollah had fired more than 100 rockets in response, saying it was one of the group's biggest rocket barrages since the hostilities began in October.

Hezbollah declared at least five attacks in response to what it called an assassination by Israel in Jouaiyya, including one in which Hezbollah fighters fired guided missiles at an Israeli military factory.

The group also said it had attacked Israeli military headquarters in Ein Zeitim and Ami'ad, and an Israeli military air surveillance station in Meron, in each case firing dozens of Katyusha rockets, according to its statements.

Sirens sounded in northern Israel.

Israeli jets hit a number of launch sites in southern Lebanon on Wednesday after projectiles were fired towards northern Israel, the military said.

The Israeli military earlier said Hezbollah had fired a barrage of around 50 launches from southern Lebanon into the Israeli-occupied Golan Heights.

In a second announcement, Israel said approximately 90 projectiles were identified crossing from Lebanon, a number of which were intercepted while others fell in several locations in northern Israel, causing fires in a number of areas.

It was not clear if the Israeli statements were referring to two separate launches.

Abdallah, the Hezbollah commander killed on Tuesday, was senior to Wissam Tawil, a high-level Hezbollah commander killed in an Israeli strike in January, said the sources in Lebanon, who spoke on condition of anonymity.

The security sources said the four Hezbollah members were likely targeted during a meeting.

Israeli strikes have killed some 300 Hezbollah fighters in Lebanon - more than it lost in 2006, when the sides last fought a major war, according to a Reuters tally which puts the number of civilians killed at around 80. Attacks from Lebanon have killed 18 Israeli soldiers and 10 civilians, Israel says.

The Israeli military says it has killed more than 320 Hezbollah members, including at least 100 targeted after field operatives gathered "precise high-quality intelligence" on them.