Singh was replying to SGPC chief Avtar Singh Makkar's letter on December 25, 2007, seeking a review of the so-called ‘black list’ containing names of persons with militant links, who took asylum abroad fearing harassment at the hands of security forces.

The lists cannot be done away with as ‘the government and our agencies have credible information of efforts being made by extremist groups to revive militancy in Punjab’, he said.

"Much of this is concentrated in countries abroad, like the UK, Germany, Canada and especially Pakistan, where such groups receive a great deal of encouragement from remnants of extremist groups as well as support from other hostile forces," Singh's letter said.