Malaysian police have deported two nationals from India wanted over an explosion on a railway line in Punjab, in a case Indian media have linked to an alleged militant plot tied to the Khalistan separatist movement seeking an independent Sikh homeland.

The Royal Malaysia Police said the duo were sent back to India on Wednesday after Indian authorities requested help locating and arresting them.

M. Kumar S. Muthuvelu, director of the police’s criminal investigation department, said the two were believed to have been involved in the detonation of an improvised explosive device on a railway line in Patiala, in India’s northern state of Punjab, on April 27.

“This action also proves that Malaysia will not become a place of refuge for any individual attempting to flee the criminal justice process,” he said in a statement.

Police said the arrests were the result of cooperation between Malaysian and Indian authorities to combat cross-border crime.

Indian media reports said the explosion was being investigated as an alleged plot linked to Pakistan’s Inter-Services Intelligence agency and pro-Khalistan networks, and that it backfired when the device planted on the railway tracks exploded prematurely, killing another suspect, Jagdoop Singh, near Bathonia village.