Three adults and several children were returning from a Halloween festival on Monday night when they encountered a group of seven youths near Sierre station, reported local paper La Nouvelliste on Wednesday.
At a bridge near the station they were encircled by the gang, who refused to allow them to carry on, said one of the women involved, mother of children in the group.
The teens were wearing hooded tops and scarves, and carrying baseball bats, she told the paper.
“I told them we were with children and simply wanted to pass by,” said the woman, but the youths refused and pushed her.
Her husband then intervened and was attacked by the youths, said the paper.
After a passer-by stopped to help, the family were able to escape, but their aggressors followed them to an apartment block.
There, the adults tried to stop the gang entering the building so the youths smashed a window, injuring the husband's hand in the process.
The gang finally fled when the police arrived, said the paper.
Valais police confirmed the incident, telling the paper that all the youths involved had been identified.
The children were left “shocked” by what happened, said the paper.