Pagers, used every day by health care professionals, became a deadly weapon Tuesday as thousands of them simultaneously exploded in Lebanon.

Lebanon blamed Israel for attacks on Hezbollah that killed 37 and wounded around 3,000, wreaking havoc on the militant group.

Officials in Lebanon reportedly have banned pagers and walkie-talkies from being brought onboard planes departing Beirut following explosions targeting Hezbollah.

The attacks in southern Lebanon follow others on Hezbollah rocket launchers and infrastructure, after Hezbollah vowed to respond to detonations of pagers and radios.

Israel carried out one of the most intense bombardments of the past year, as warplanes launched 70 airstrikes, Lebanese security officials said. The barrage came shortly after Hezbollah’s leader vowed to respond after explosions of pagers and walkie-talkies killed at least 37 people.

By Laila Bassam and Maya Gebeily BEIRUT/JERUSALEM (Reuters) -Israeli warplanes carried out late on Thursday their most intense strikes on southern Lebanon in nearly a year of war, heightening the conflict between Israel and Lebanese armed group Hezbollah amid calls for restraint.