Ten hardcore Sikh militants holed up in Pakistan for many years are under pressure from its intelligence agencies to revive Sikh militancy in India, Indian intelligence sources aver.

"Pakistan is so desperate to reactivate the militant leaders that it has told them to either create turmoil in India -- or quit Pakistani territory for good," said a senior security official who spoke only if he was not identified.

Security officials say the list of 10 names have been shared with several police forces, including those in Delhi and Punjab, where a bloody decade-long separatist campaign was finally put down by 1993.

"These terrorists are on our radar," Punjab's Additional Director General of Police Hardeep Dhillon told IANS on telephone from Chandigarh.

Prominent among those living in Pakistan are Babbar Khalsa International's Wadhawa Singh and his aides Ratandeep Singh and Mehal Singh. Others include Jagtar Singh Tara of Khalistan Tiger Force, Ranjit Singh Meeta of Khalistan Zindabad Force, Gajinder Singh of Dal Khalsa, Paramjeet Singh Panjawar of Khalistan Commando Force, Lakhweer Singh Rode of International Sikh Youth Federation, Harminder Singh Mintu of Khalistan Liberation Force and Harmeet Singh of Komagata Maru Dal.

Pakistan's Inter-Services Intelligence (ISI) has for decades controlled both Sikh and Kashmiri separatists, providing them weapons, training,cash as well as sanctuary, say Indian security agencies.

Once the Khalistan movement was put down, some of the surviving militants escaped to Pakistan.

This has been corroborated by Lashkar-e-Taiba member Abdul Karim Tunda, who is now in Delhi Police custody, intelligence sources told IANS. Tunda has also told Indian interrogators that the Pakistani intelligence has provided shelter to small and big terrorist groups to execute bombings in India.

Delhi's Special Commissioner of Police S.N. Srivastava told IANS: "Wadhawa Singh, Ratandeep Singh and Mehal Singh are the most wanted Sikh  extremists."

Tunda confessed that he had been assigned by Ratandeep Singh to carry out bomb attacks in India. Tunda also said that the Babbar Khalsa International had demanded explosives before the Commonwealth Games in Delhi in 2010 -- and he sent the consignment.

Intelligence sources say that the Sikh militants in Pakistan are in touch with "extremist minded" pro-Khalistan expatriates based in the West, particularly in Canada. The pro-Khalistan expatriates are known to fund the extremists -- also with the mission of reviving militancy in Punjab.

Over the last four years, Punjab Police has busted over a dozen modules of terrorist groups trying to revive terrorism in the state. Some suspects have been arrested and weapons and ammunition sezied from them.

The attempts to revive terrorism has not found many takers in Punjab.

In desperation, terrorist outfits, mainly Babbar Khalsa International and and Khalistan Commando Force, have tried to bring in youths from other states and countries for terror activities in Punjab.

BKI's Jagtar Singh Hawara, who escaped from a Chandigarh prison in January 2004, tried to revive terrorism but failed. He was later arrested by Delhi Police from Patiala.

When the Khalistan campaign raged for a decade until 1993, over 25,000 people were killed. The last big terrorist strike was the assassination of then Punjab Chief Minister Beant Singh in Chandigarh Aug 31, 1995.