Lightning sparks Vic house fire

A lightning strike is believed to have sparked a fire that destroyed a Melbourne home.

Flames from a tree branch, likely to have been set ablaze by lightning, spread to a Prahran house about 2am (AEDT).

Fire crews arrived to find the top floor well alight and flames threatening nearby homes.

Residents from several homes were evacuated for two-and-a-half hours.

The damage bill has been estimated at $850,000.