Idaho State Police troopers are on the scene of a six-vehicle crash on Interstate 84, between the Franklin Blvd. and Northside Blvd. exits.
It happened about 1:50 p.m., according to an ISP dispatcher.
The dispatcher says, so far, only one person has been transported by ambulance to a local hospital.
No word yet what caused the collision. Police say an initial crash had happened and then other cars began crashing behind them.
The eastbound left lane of the Interstate has been shut down.
Nampa Police officers and Nampa Fire Department crews are assisting ISP.
Traffic is backed up in both directions.
Drivers are asked to avoid the area if possible.
No further details were immediately available.