The body of Hezbollah leader Hassan Nasrallah, killed in an Israeli air strike on southern Beirut, has been recovered, a source close to the movement told AFP on Sunday.

"His body was recovered on Saturday and was placed in a shroud on Sunday after being washed," the source said, requesting anonymity.

"The funeral ceremony and his burial have not yet been arranged," the source added.

Before his death on Friday when Israeli jets attacked Hezbollah's heartland in the south of the Lebanese capital, Nasrallah was considered the most powerful man in the country. 

For more than three decades he headed the Iran-backed movement that was Israel's sworn enemy.

Friday's air strike also killed Ali Karake, the group's top commander in southern Lebanon, Hezbollah said on Sunday.

It has not named others who died alongside Nasrallah and Karake.

However, Israel's military said on Sunday that "more than 20 other terrorists of varying ranks" were also killed in the attack.

The authorities in Lebanon gave a provisional toll of six dead, but given the scale of the destruction the number of dead is likely to be higher. 

Beirut's southern suburbs, and south and east Lebanon have been subject to intense Israeli bombardment since Monday, with the country's health ministry reporting more than 700 people killed and hundreds of thousands displaced.