Two peacekeepers serving with the United Nations Interim Force in Lebanon (UNIFIL) were killed on Monday in an explosion of unknown origin in southern Lebanon, the organization said.

The blast destroyed their vehicle near the municipality of Bani Hayyan, UNIFIL said in a statement.

Two other peacekeepers were injured, one of them seriously, it said.

The incident marks the second fatal attack involving UNIFIL peacekeepers within 24 hours, the organization said.

On Sunday, an Indonesian peacekeeper was killed and another injured when a projectile exploded at a UN position in southern Lebanon, UNIFIL said.

Fighting between Israel and the Iran-backed Hezbollah has flared up again in Lebanon amid the Iran war, with UN peacekeepers repeatedly caught in the crossfire along the border.

The United Nations has deployed peacekeepers to the border region since 1978. The mission currently includes around 7,500 troops from nearly 50 countries.

UNIFIL said it had launched investigations into both incidents and called on all parties to uphold their obligations under international law and ensure the safety of UN personnel and property.

It warned that deliberate attacks on peacekeepers could constitute serious violations of international humanitarian law and may amount to war crimes.

The mission expressed its condolences to the families and colleagues of the victims and wished a swift recovery to the injured, stressing that "no one should ever have to die serving the cause of peace."

Israeli shelling kills Lebanese soldier, army says

Separately, the Lebanese army said one of its soldier had been killed in an Israeli attack in southern Lebanon.

Several others were wounded, it added.

The Israeli military said, in response to an inquiry, that it was investigating the allegations.

The Lebanese army is not an active participant in the ongoing conflict between Israel and Hezbollah. Nevertheless, several Lebanese soldiers have already been killed in the recent escalation.

The Israeli army also reported the death of an Israeli soldier in southern Lebanon, saying the 19-year-old died on Sunday. Israeli media reported that he was killed by Hezbollah rocket fire.

According to the Israeli military, several Lebanese soldiers were also wounded, some seriously, by rocket fire from the militia.

Israel strikes Beirut's southern suburbs, killing one

Meanwhile, an Israeli airstrike on the Rahab area in Beirut's southern suburbs killed one person and wounded 17 others, Lebanon's Health Ministry said.

In a statement, the ministry's emergency operations centre said the strike resulted in 10 Lebanese nationals being injured, along with six Syrians - including four children - and one Kenyan woman.