Israeli Prime Minister Benjamin Netanyahu on Tuesday accused Lebanon's Hezbollah of manufacturing weapons next to a "gas station" in Beirut, warning of "another tragedy" if it explodes.

Israel has repeatedly accused the Shiite movement Hezbollah, backed by Israel's arch-foe Iran, of building missiles to attack the Jewish state.

In a video speech from Jerusalem broadcast to the UN General Assembly in New York, Netanyahu presented a map with coordinates he said showed a "secret weapons depot" in Beirut's southern suburb of Jnah, a stronghold of the movement.

Beirut is still reeling from an August 4 explosion when a huge stockpile of ammonium nitrate exploded in the port, killing more than 190 people, wounding thousands and ravaging large parts of the city.

The Israeli illustrations showed what Netanyahu said was a weapons depot sandwiched between two compounds.

The alleged precision missile factory is "a few metres away from a gas station" on one side, and 50 metres (164 feet) from a "gas company" on the other.

"If this thing explodes, it's another tragedy," Netanyahu said.

The site is also close to Beirut's international airport.

The Israeli images appeared to show cooking gas depots, but there are also petrol stations nearby according to Google Maps.

Netanyahu showed details of two other alleged missile production sites, in Beirut's Laylaki and Choueifat districts, which he said were located under apartment buildings.

"I say to the people of Lebanon, Israel means you no harm," he added.

"But Iran does. Iran and Hezbollah have deliberately put you and your families in grave danger."

Israel and Lebanon are technically in a state of war, and their common border, patrolled on the Lebanese side by a UN force, remains the scene of sporadic attacks.

Hezbollah and Israel fought a devastating month-long war in 2006.

Israel has also carried out dozens of air strikes on Hezbollah targets in neighbouring Syria where the group is fighting alongside the government of President Bashar al-Assad.