HILLSBOROUGH - A gas leak from an underground pipeline is expected to cause heavy delays in Hillsborough tonight and tomorrow.

Emergency management officials are trying to pinpoint the source of a gas leak in an underground pipeline run by Buckeye Partners.

State and local officials spent most of the day investigating reports that raw gasoline leaked into the township's sanitary sewer system. The investigation began this afternoon near Route 206 northbound and New Amwell Road.

Many residents in the area reported the strong smell of gasoline.