Israel carries out the most severe attacks on Lebanon, the US and Britain call for an urgent solution

Israeli warplanes late Thursday carried out the most intensive strikes on southern Lebanon in nearly a year of war, Lebanese security sources said, a development that appears to have further escalated the conflict between Israel and the Lebanese armed group Hezbollah, despite calls for restraint.

The White House said a diplomatic solution was achievable and urgent. Britain also called for an immediate ceasefire between Israel and Hezbollah. The US is "fearful and concerned about the potential escalation of the conflict," White House spokeswoman Karine Jean-Pierre told a news conference.

The intense shelling followed attacks earlier in the week that Lebanon and Hezbollah blamed on Israel, which blew up the militant group's hand-held radios and beepers, killing 37 people and wounding around 3,000 others in Lebanon.

In Thursday's operation, Israel dropped dozens of bombs across southern Lebanon, three Lebanese security sources said. There were no immediate reports of casualties.

Israeli radio stations reported that dozens of warplanes struck Hezbollah targets, including about 100 rocket launchers.

The Israeli military did not confirm this, but said earlier it had hit dozens of Hezbollah targets, including rocket launchers and weapons depots in southern Lebanon.

In a televised address on Thursday, Hezbollah leader Hassan Nasrallah said the explosions of communications equipment on Tuesday and Wednesday "crossed all red lines".

"The enemy went beyond all control, law and morality," he said, adding that the attacks "can be considered war crimes or declarations of war."

Israel has not commented directly on the blasts of beepers and hand-held radios, which security sources say may have been carried out by Israel's Mossad spy agency, which has a long history of carrying out sophisticated attacks on foreign soil.

The Lebanese mission to the UN said in a letter to the Security Council on Thursday that Israel was responsible for detonating the devices via electronic messages and explosives placed in them before they reached Lebanon.

Regarding this issue, the 15-member UN Security Council will meet on Friday.