Investigators are still unsure what caused a car to explode in a Melbourne driveway, seriously hurting the driver.

The 29-year-old man suffered leg injuries when his late-model car exploded outside his Dallas home just after 9am on Thursday.

Nearby houses have been evacuated and bomb squad officers using a bomb disposal robot are checking for secondary and unexploded devices.

Bomb squad at scene of Melbourne car explosion @7NewsMelbourne . Man badly injured pic.twitter.com/NNHkuzxdCR

— Lynne Scrivens (@lynnescrivens) May 29, 2014

Senior Sergeant Rod Luke said investigators were unsure how the vehicle exploded and could not get in to assess the area until it had been declared safe. “It is too early to determine what’s exactly happened. We haven’t cleared the crime scene,” Sen Sgt Luke told reporters. “We’re waiting for the bomb response unit to make sure it’s safe.”

Dallas car explosion – suspicious, bomb squad en route. Nearby residents evacuated.@9NewsMelb pic.twitter.com/y5xCJLIc0R

— Alexis Daish (@LexiDaish) May 29, 2014

The 29-year-old was taken to the Royal Melbourne Hospital with serious but not life-threatening burns to his lower body.

Residents in the street have not been told when they will be able to return to their homes.