A plane heading to Tel Aviv from Dubai was forced to make an emergency landing in Saudi Arabia on Wednesday, after one of the pilots allegedly tried to crash the plane and kill everyone onboard.

North Korean leader Kim Jong Un is understood to be "extremely obese", Seoul's spy agency said Wednesday, citing its latest assessment of the reclusive leader's health.

A heavy smoker who has long been obese, Kim's health is closely watched internationally as his sudden death could raise questions over succession and stability in the nuclear-armed state.

Israeli leaders said on Wednesday that a "jihadist" pilot had aimed to crash a flydubai plane with mostly Israeli passengers, who overpowered him and prevented a "major disaster".

Israeli Prime Minister Benjamin Netanyahu said Wednesday that one of the pilots of a flydubai plane bound for Tel Aviv had planned to crash it and kill its mostly Israeli passengers, who stopped a "major disaster."

"During the flight, as they approached the country, one of the pilots stabbed the other pilot, and apparently tried to crash the plane with everyone on board," Netanyahu said in a video message, calling the passengers "heroes" who "prevented a major disaster."

A passenger on a rerouted flydubai flight that was bound for Tel Aviv said one of the pilots tried to crash the plane and kill everyone on board, after both pilots were found to be wounded on landing in Saudi Arabia.

In the first comment by an official, Israel's far-right national security minister Itamar Ben Gvir alleged an attempted "terrorist" attack in the incident, in which none of the passengers reported injuries.

The emergency landing Wednesday of a Tel Aviv-bound flydubai flight was due to a "terrorist" who wanted to crash the plane and kill Israelis, Israel's far-right national security minister said.

"The naive notion that our enemies cherish life and that we should pity them received another reminder this morning in the form of a terrorist who planned to crash a plane and murder the 180 Israelis on board," Itamar Ben Gvir said in a statement.

Gaza City's Al-Shifa Hospital said an Israeli airstrike targeting a vehicle killed five people on Wednesday, with the territory's civil defense agency confirming the toll.

Al-Shifa reported that "five martyrs and 13 injured arrived to the hospital following an Israeli airstrike that targeted a vehicle near the destroyed cabinet headquarters in the Tel al-Hawa neighborhood". AFP has contacted the Israeli military for a response.

The Lebanese military said on Wednesday that the explosion of an unknown object wounded a soldier and three civilians, after initially saying it was an Israeli strike.

"A soldier and three civilians were wounded in the Nabatieh al-Fawqa area as a result of an explosion while the army was escorting residents to inspect their properties in the area," the army said in a statement.

Israel's opposition chief early Wednesday accused Prime Minister Benjamin Netanyahu of fear-mongering after he alleged that enemies may attack before October 27 elections.

Netanyahu, who polls show is in a close race to hold on to power, has issued warnings in recent weeks to Iran, the militant groups Hamas and Hezbollah and even the West Bank-based Palestinian Authority, vowing retaliation in case of an attack.

Hezbollah denied on Wednesday any connection to a cell that Syrian authorities said they had dismantled in the country's south and which they accused of being affiliated with the Lebanese group.

A statement from the Iran-backed group's media office said it "categorically denies any relationship or connection between Hezbollah and the alleged cell" and emphasized that "it has no presence whatsoever on Syrian territory and has no involvement in any security or military activity there."