A senior railway official said that NRMU members sat on a dharna at different places including Jalandhar, Amritsar, Ludhiana, Ferozepur and Jammu Tawi, affecting the rail traffic for about an hour.
"The movement of 7-8 trains was affected this morning. The dharna was lifted by the union employees after an hour and normal rail traffic has been restored," Ferozepur's Divisional Railway Manager, N C Goel said over phone.
NRMU leaders have maintained that five of their men got injured in the attack and had to be admitted to a Ludhiana hospital.
URMU, however, has claimed that their men were attacked first and four of their members were injured and admitted to a hospital in Amritsar.
Both groups had submitted separate complaints to the police. The NRMU has been demanding immediate arrest of the alleged culprits. They have alleged that no action has been taken so far against the accused.