Lebanon's Hezbollah warned Israeli residents to evacuate towns within 5 km of the border between the countries in a message posted on its Telegram channel in Hebrew early on Friday.
Hezbollah's message came less than a day after Israel warned residents to leave Beirut's southern suburbs, prompting an exodus from a swathe of the capital known as Dahiyeh.
Lebanon was pulled into the war in the Middle East on Monday, when Hezbollah opened fire, sparking Israeli airstrikes focused on Beirut's southern suburbs and on southern and eastern Lebanon.
"Your military's aggression against Lebanese sovereignty and safe citizens, the destruction of civilian infrastructure and the expulsion campaign it is carrying out will not go unchallenged," Hezbollah said.
Israel has said it will not evacuate its border towns and has sent more soldiers into Lebanon, saying this was a defensive measure meant to protect its citizens who live nearby.

US House rejects war powers resolution, backs Trump on Iran war
GCC and EU ministers urge immediate halt to Iranian attacks
Trump wants say on Iran's next leader
US, Venezuela agree to re-establish diplomatic ties
British PM Starmer to send four Typhoon jets to Qatar