A bomb was found on the tracks near the Jungshahi train station in Thatta Sunday morning.
The Bomb Disposal Squad was called in from Hyderabad to disarm the device. The 500 gramme bomb was planted on the railway track three kilometres away from the station.
Trains were stopped for three hours but have now been allowed to operate again.
Thatta SSP Shabbir Sethar confirmed the news and said the police were tipped off about an explosive at the train station early Sunday morning. A heavy contingent of police are currently at the station.
SSP Sethar said that 10 minutes after the police found the bomb, a train was scheduled to cross the track. The Shalimar Express was halted before it reached the track. He said the explosive had a remote control device attached to it, leading them to believe the people who planted it were nearby.
They searched the area and arrested one suspect. They also seized some items from the man, who the police say is from another province.