More soil contamination from fossil fuel has been found on land formerly occupied by a U.S. military facility in Okinawa and there are fears the contaminants have spread via groundwater, according to an inspection report of the local defense bureau obtained Saturday.

Contamination by what appeared to be jet fuel and gasoline was found in the northern part of Camp Kuwae, according to the Okinawa Defense Bureau's report for this year. Some of the land used by the base was handed back to Japan in 2003.

Under the Japan-U.S. Status of Forces Agreement, the United States has no obligation to clean up environmental contamination or provide compensation when returning base land.

The report says groundwater caused the contaminants to spread over a "wide area," and the level of fumes exceeded the limit set by the bureau and a local government in 19 of 20 soil samples taken from the 38-hectare site.

Of those samples, six contained more oil residues than allowed under local regulations. Such oils are believed to be nonvolatile gas oil and lubricant oil, the report says.

The bureau said it plans to conduct a more detailed inspection.