JERUSALEM/BEIRUT, June 12 (Reuters) - Hezbollah fired big barrages of rockets at Israel on Wednesday and vowed to ramp up its attacks in retaliation for an Israeli strike which killed a senior Hezbollah field commander, as the conflict across the Lebanese-Israeli border escalated sharply.

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 fuelled concern of a bigger confrontation between the heavily armed adversaries.

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

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

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.