Israeli warplanes break sound barrier over Beirut

Israeli warplanes have broken the sound barrier three times over Beirut in less than 30 minutes, leading to loud booms that sent people in the city running for cover just ahead of a speech by the head of the Hezbollah group.

Israeli warplanes flew low over the Lebanese capital, with witnesses saying they could see the planes with the naked eye.

The booms were the loudest heard in Beirut in years.

One Reuters reporter saw people at a cafe in Beirut's Badaro district scatter as the sound reverberated through the city.

Hezbollah chief Sayyed Hassan Nasrallah was set to begin an address about 5pm to mark one week since the killing of the Lebanese armed group's top military commander Fuad Shukr in an Israeli strike in Beirut's southern suburbs.

Hezbollah has promised to respond to the killing, which came just hours before the assassination of Hamas leader Ismail Haniyeh in Tehran in an operation blamed on Israel but which Israel has not confirmed or denied undertaking.

The twin killings have pushed the region to the brink of war, with Iran also vowing a painful response.