Security personnel aboard various trains and at railways stations across Punjab were put on high alert on Monday following the explosion on Delhi-Attari special train in Panipat in Haryana, which killed 64 people, including Pakistani nationals.
Various security agencies, including Punjab Police and the Railway Protection Force have been asked to remain on maximum alert, Punjab police sources said.
They have been asked to be on the look out for suspicious objects and persons as part of attempts to check further incidents.
The checking in trains coming from Jammu has been ordered to be stepped up, the officer said.
A senior Punjab Police officer told PTI here that they were also probing the blast in the Attari special train from Delhi, which is the link train for the Lahore-bound Samjhauta Express.
Security in the Delhi-Lahore and Amritsar-Lahore buses was also being tightened.
At least 64 people were killed, some of them Pakistani nationals in explosions in the Attari special train. The train runs non-stop from Delhi to Attari where the passengers are shifted to the Samjhauta Express, which goes to Lahore after customs and immigration clearances.