New Delhi - In the first 40 days of the year, 18 sabotage cases were reported on Indian railways, an increase that worries the authorities, today revealed a sector official.

Cases of man-made obstructions, roadway manipulation and plaque removal have been detected, an official source told The Times of India.

Sabotage attempts in divisions Lucknow, Mumbai, Waltair, Allahabad and Malda were thwarted by security personnel and security forces, he said.

Speaking to the Lok Sabha (Lower House of Parliament), the Railway Minister, Suresh Prabhu, admitted his concern about the 'unusual activities' reported in recent days.

Prabhu noted that seven attempts to exploit railroad lines were aborted.

In a letter dated 23 January, Prabhu asked Interior Minister Rajnath Singh to investigate the recent series of train accidents and cited six incidents in which there is 'a possibility of criminal interference by outsiders.'

On January 21, 39 people died after the derailment of nine train wagons in Andhra Pradesh state. On November 20, another 151 were killed by a similar incident occurred in Kampur district, Uttar Pradesh.

At the end of last year, the Sealdah-Ajmer express was also derailed near Rura station, leaving over 50 passengers injured.