CHICAGO (CBS) — Palos Park police responded to a call for help when a passenger attacked a Metra employee Monday, police say.

The incident happened shortly before 6 p.m., and all train traffic was halted.

The offender was taken into custody. Medical assistance was requested for both the offender and the victim, but the victim refused treatment, according to police.

No other passengers were injured or placed in danger and service resumed.

Palos Park police said they handed the case over to Metra and held the alleged offender for Metra.

Metra declined to comment until yet.