By Maya Gebeily, Tom Perry and James Mackenzie

BEIRUT/JERUSALEM (Reuters) -An Israeli airstrike targeted a Hezbollah commander in the southern suburbs of Beirut on Tuesday, two security sources in Lebanon said, killing six people after Israel’s military chief said the Iran-backed group would be given no breathing space.

Israel struck the Hezbollah-controlled area of the Lebanese capital for a second consecutive day after mounting a new wave of airstrikes on Hezbollah targets in Lebanon, increasing fears that nearly a year of conflict would explode into an all-out war and destabilise the oil-producing Middle East.

After nearly 12 months of war against the Palestinian militant group Hamas in Gaza on its southern border, Israel is shifting its focus to the northern frontier, where Hezbollah has been firing rockets into Israel in support of Hamas, which is also backed by Iran.

The sources in Lebanon declined to identify who had been targeted in Tuesday’s strike on Beirut and said his fate was unknown. The health ministry gave an initial toll of six dead and 15 wounded in the strike.

The Israeli military, which carried out airstrikes against Hezbollah on Monday which Lebanese authorities said killed more than 500 people, said it had carried out a strike in Beirut on Tuesday, but gave no details.

The airstrike hit a building in the usually busy Ghobeiry neighbourhood. One of the security sources shared a photo showing damage to the top floor of the five-storey building.

Israel’s military chief said attacks on Hezbollah would be accelerated.

“The situation requires continued, intense action in all arenas,” said Military Chief of General Staff Herzi Halevi after holding a security assessment.

Lebanese authorities said 558 people had been killed, including 50 children and 94 women, in Israel’s airstrikes on Monday. A further 1,835 were wounded, they said, and tens of thousands more have fled for safety.

The casualty tolls and constant pressure from the most powerful and advanced military in the Middle East has spread panic in Lebanon, which suffered from devastating destruction when Israel and Hezbollah fought in 2006.

“We are waiting for victory, God willing, because as long as we have a neighbour like Israel, we can’t sleep safely,” said Beirut resident Hassan Omar.

Afif Ibrahim, a taxi deriver from southern Lebanon, was defiant.

“They (Israel) want us (Lebanese) to kneel, but we kneel only to God in our prayers; we bow our heads to no one but God,” he said.

GROWING CALLS FOR DIPLOMACY

Calls for diplomacy are growing as the conflict worsens, with UN human rights chief Volker Turk urging all states and actors with influence to avert further escalation in Lebanon.

“I believe that we can still find a path forward to get de-escalation between Israel and across that northern border between Israel and Lebanon and bring about a diplomatic solution that allows people to return to their home,” White House national security adviser Jake Sullivan told MSNBC.

The fighting has raised fears that the United States, Israel’s close ally, and regional power Iran, which has proxies across the Middle East – Hezbollah, Yemen’s Houthis and armed groups in Iraq – will be sucked into a wider war.

The strikes have piled pressure on Hezbollah, which last week suffered heavy losses when thousands of pagers and walkie-talkies used by its members exploded in the worst security breach in its history.

The operation was widely attributed to Israel, which has a long history of sophisticated attacks on foreign soil. It has not confirmed or denied responsibility.

Hezbollah’s media office said on Tuesday that Israel was dropping leaflets with a “very dangerous” barcode on them onto Lebanon’s eastern Bekaa Valley, warning that scanning it by phone would “withdraw all information” from any device.

There was no immediate comment from the Israeli military. Hezbollah’s media office did not say if anything else was written on the flyers.

Israel’s intelligence and technological prowess has given it a strong edge in both Lebanon and Gaza. It has tracked down and assassinated top Hezbollah commanders and Hamas leaders.

On Tuesday, Israel’s military said about 55 projectiles had crossed into Israel in the latest attacks, but the majority were intercepted.

Hezbollah said it had bombed the logistical warehouses of the 146th Division in the Naftali base with a rocket salvo.