Hezbollah said on Tuesday it had launched a volley of rockets at an Israeli aerial surveillance base in response to the Israeli military’s deepest attack yet into Lebanese territory.

Israeli warplanes struck the Bekaa Valley on Monday, killing at least two Hezbollah members in the military’s furthest reach into Lebanese territory since hostilities erupted with the Iran-backed group last October, sources in Lebanon said.

The Israeli army said it had struck Hezbollah air defences in the area in response to the downing of an Israeli drone, which Hezbollah said it had shot down with a surface-to-air missile earlier on Monday.

In retaliation for the Bekaa strikes, Hezbollah fired 60 rockets on Monday at an Israeli army station in the Israeli-occupied Golan Heights. The group did not say how many rockets were fired on Tuesday morning but said it was a “large volley”.

The attacks marked an intensification of the worst violence between the heavily armed Hezbollah and Israel since their 2006 war, fuelling concerns about a potential escalation and a widening of Israel’s war in Gaza to other parts of the region.