TORONTO -- Toronto police are looking for the cause of an overnight explosion that destroyed a food stall at the Canadian National Exhibition grounds.

The stall, which was in a vacant lot, was destroyed in the blast and reports say it may have been caused by a generator or a propane tank.

But Staff Sgt. Chuck Konkel says the cause is unknown and police are talking to experts to look at what could have caused the explosion at about 4 a.m.

There were no injuries in the blast, which Konkel says occurred in an area where many people could be during daytime hours.

He says the explosion caused $30,000 in damage and that police continue to investigate.