Twelve people died Monday when a vehicle exploded on Turkey's southern border with strife-torn Syria, but it is still not clear if the blast was an attack or the accidental explosion of a vehicle loaded with explosives, NTV television said.

The vehicle that blew up had Syrian registration and the blast killed Turkish border guards as well as civilians from both Turkey and Syria.

Government spokesman Bulent Arinc confirmed the death toll and said that 28 other people had been wounded, speaking at a press conference broadcast live by NTV.

Three of the dead were Turkish citizens and nine were Syrians, Arinc said.

"What we know is that a van that had arrived from the Syrian side exploded, but we still don't know the type of explosive or if it was an individual act or one by an organization, or if it had political motives or not," the spokesman said.

He said that authorities are continuing to investigate the incident and downplayed the expressed opinion of opposition lawmaker Hasak Akgol that it could be a suicide attack, calling that a "hasty conjecture."

The explosion occurred about 1300 GMT in Reyhanli, about 40 meters (yards) inside Turkish territory on the border with Syria. The blast caused a fire that destroyed about 15 other vehicles, including some that were transporting humanitarian supplies to Syria, where tens of thousands have died in a conflict that began almost two years ago. EFE