An inter-city train driver in Lahore has been suspended after he made an unscheduled stop to pick up some yoghurt.
A video of the driver's assistant collecting the snack from a street stall before climbing back into the carriage has been circulating on social media.
The incident on Monday raised questions about the safety and regulation of railways in Pakistan, where accidents are common due to mismanagement and neglect.
"When you stop a train in the middle [of the tracks] it becomes a safety issue. Safety is our priority. We cannot tolerate anything which compromises safety," Syed Ijaz-ul-Hassan Shah, a spokesman for the railway ministry, told AFP on Wednesday.
The passenger service had started its journey in the eastern city of Lahore and was moving south towards Karachi.
In a statement, Federal Minister of Railways Azam Khan Swati warned that he will not "allow anyone to use national assets for personal use".
A railway official admitted to AFP that such incidents are not uncommon in Pakistan, and that oversight is often lacking.
More than 60 people were killed in June when a train hurtling through farmland smashed into the carriages of another service that had derailed minutes earlier.