The displacement of hundreds of thousands of people in Lebanon is "devastating", a U.N. migration official has said, warning international support was falling short of the needs, amid intense Israeli bombing.

After a year of cross-border fire between Israel and Hezbollah, which launched attacks on Israel in support of its ally Hamas in Gaza, Israel last month escalated attacks on what it says are Hezbollah targets in Lebanon's south, east and south Beirut.

The UK government on Friday condemned firing by Israeli forces on a United Nations peacekeeper base in Lebanon, urging all parties in the conflict to "comply with international law."

"We were appalled to hear those reports and it is vital that peacekeepers and civilians are protected," a spokeswoman for Prime Minister Keir Starmer told reporters.

Lebanese Christian Joseph Jarjour was hoping for a peaceful retirement at home in south Lebanon, but has instead found himself caught in the crossfire of the Israel-Hezbollah war.

"We're trapped," said the 68-year-old retired teacher in the southern village of Rmeish, around two kilometers (one mile) from the Israeli border.

Hezbollah senior leader Wafiq Safa was seriously injured and is in critical condition following the deadly Israeli airstrikes that targeted two buildings in Beirut’s Noueiri and Bourj Abi Haidar areas, sources told Sky News Arabia on Friday.

Rescue workers searched through the rubble of a collapsed building in central Beirut on Friday morning, hours after two Israeli strikes hit the Lebanese capital, killing at least 22 people and wounding dozens.

The air raid was the deadliest attack on central Beirut in over a year of war, hitting two residential buildings in neighborhoods that have swelled with displaced people fleeing Israeli bombardment elsewhere in the country.

Caretaker Prime Minister Najib Mikati on Friday urged the United Nations to pass a resolution calling for an "immediate" ceasefire between Israel and Hezbollah.

Mikati told reporters the foreign ministry would ask the U.N. Security Council to issue a resolution demanding a "full and immediate ceasefire" and that his government was committed to Resolution 1701 which was adopted in 2006 and called for the Lebanese army and peacekeepers to be the only armed forces deployed in the south of the country.

Hezbollah said it launched a drone attack Friday on a military base in north Israel's Haifa, a day after deadly strikes in the heart of Beirut and as the group battles Israeli forces on the border.

Hezbollah launched "an air attack with a group of explosive-laden drones" towards the "air defense command base" in Haifa, "responding to" Israeli attacks on "cities and villages and civilians," the group said in a statement.

An anti-tank missile fired from Lebanon killed a young man from Thailand in the north of Israel early Friday, Israel’s paramedic service said.

Magen David Adom, the paramedic service, said that the 27-year-old was killed by a missile that hit agricultural land.

Israel is recommending that the U.N. peacekeeping force in southern Lebanon move 5 kilometers (3 miles) north to avoid intensified fighting between its forces and Hezbollah fighters.

Israel’s U.N. Ambassador, Danny Danon, announced the recommendation in a statement following the wounding of two U.N. peacekeepers from the force known as UNIFIL as a result of Israeli tank fire. UNIFIL also reported that its headquarters and nearby positions “have repeatedly been hit” by Israeli forces.

The White House says it is “deeply concerned” about a report from the United Nations peacekeeping mission in southern Lebanon that Israeli forces opened fire on locations where peacekeepers were working and injured two of them.

“We are deeply concerned about reports that Israeli forces fired on two positions and a tower used by U.N. peacekeepers in Lebanon,” a spokesperson for the White House National Security Council said in a statement Thursday. “We reached out immediately to our Israeli counterparts about it, and pressed them for more details.”