Hezbollah admits Israel dealt a severe blow with exploding pagers and walkie talkies, but neither side seems to heed U.S. calls to avoid a wider war.

Lebanon and Hezbollah have blamed Israel for the attacks on Tuesday and Wednesday that killed 37 people and wounded around 3,000, although Israel has not directly commented on the attacks, which security sources say were probably carried out by its Mossad spy agency.

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.

Israeli Defense Minister Yoav Gallant ushered in what he called a “new phase” in the war with regional Islamist groups and said troops would be diverted to the Lebanese border, an indication that long-held fears of a wider conflict may soon be realized.

A senior U.S. official has confirmed to Fox News that Israel is behind the explosions of pagers used by members of Hezbollah in Lebanon.

Deadly Israeli attacks that blew up Hezbollah radios and pagers crossed all red lines, the leader of the heavily armed Iran-backed Lebanese movement said on Thursday, as the United States called for restraint and urgent de-escalation.