A motorcyclist was killed early Wednesday evening in a crash that has had I-4 reduced to one lane in each direction for several hours in northeastern Polk County.

According to the Polk County Sheriff's Office, a Polk sergeant saw a motorcyclist driving erratically while entering the I-4 westbound on-ramp from U.S. 27. The sergeant turned on his lights and sirens and began to pull the driver over.

But the motorcyclist revved his engine and increased his speed, the sergeant reported. The sergeant said he then turned off his sirens and lights and did not give pursuit.

A sheriff's office spokesperson said a Florida Highway Patrol trooper saw the motorcycle speeding but was unable to clock the speed because the motorcyclist was going too fast. The crash occurred shortly thereafter around mile marker 51, two to three miles west of U.S. 27.

There were no other details about the crash. 

An investigation is underway.