Police in Northern Ireland have launched an investigation after a train conductor was indecently assaulted on the Belfast to Derry line last Saturday.

The PSNI say the woman had intervened with a group of rowdy male passengers when one of the men grabbed her.

She was also verbally abused.

The conductor was then grabbed for a second time by another member of the group as they were leaving the train.  

The PSNI said it was an appalling attack, which left the woman extremely shaken and upset.

Police are appealing for any witnesses to the incident to contact them.