According to railway officials, inquiries about the anti-collision device - developed by the Konkan Rail Corporation Ltd (KRCL) - have also come in from Indonesia and South Africa.
A A Bhatt, chief signal & telecom engineer for KRCL, said Pakistan Railways was worried about the rising number of train collisions in that country in recent years.
"The ministry has informed Pakistan and other countries that the technology, although in use, is yet to be formally commissioned and only then can we allow these countries to use the device," he said.
Meanwhile, the Railways have got a patent for the ACD in South Africa while the US has sought clarifications from the ministry on it.
The ACD warns trains fitted with the equipment in advance about the movement of another train in the vicinity.
If the trains are on a collision course, both the trains brake automatically. The device transmits electronic signals that warn a train in the vicinity about the train's presence and also picks up signals emitted by other trains.
According to Bhatt, apart from the Konkan Railways, more than 1,000 ACDs have been installed in the North East Frontier Region, of which as many as 300 have been fitted onto locomotives.
The KRCL has also surveyed around 1700 km under the southern, south central and south western railways for fitting trains plying through these regions with the ACD. Chennai-Ernakulam, Jolarpettai-Bangalore and Hubli-Vasco (Goa) are the three stretches that have been earmarked for being ACD-enabled.