The crowd was later dispersed by police, a Western Railway official said.
The incident comes over a month after hundreds of migrant workers had assembled near the Bandra station over their demand that arrangements be made for them to return to their native places in the wake of the coronavirus-enforced lockdown.
In a video clip of Tuesday's incident that went viral on social media, a large number of migrants were seen carrying their luggages and running towards the gate of the Bandra Terminus.
The crowd started gathering in the area around 11 am, sources said.
The Western Railway in a statement later said a Shramik Special train was scheduled for Purnia from the Bandra Terminus in which passengers registered with the state authorities were to travel.
However, many people, who were not registered and not called by the state authorities, gathered on a road and a bridge near the station, it said.
"The bonafide passengers were checked and allowed to enter the station by the state machinery. The train left the Bandra Terminus around 12 noon with 1,700 labourers and their families who were entitled to travel," Western Railway's Chief Public Relations Officer Ravinder Bhakar said.
The crowd outside the station was later dispersed by police, a railway official said. KK GK GK