India has already made a clear distinction between the Mumbai terror attacks and Samjhauta train blasts, and that  the two were "very different" and at some stage Islamabad needs to "come clean" on this.

Asserting that India has provided enough evidence to show involvement of not only non-state actors but also of official hierarchy in 26/11 attacks, government sources said Singh will raise the issue of terrorism, which is of prime concern to the country, with Pakistan President Asif Ali Zardari, who is arriving in Tehran tomorrow to participate in the 16th NAM summit.

The government sources said other bilateral issues will also be discussed during the Singh-Zardari meeting. Asked about Pakistan equating the Mumbai attacks, in which 166 people were killed, with Samjhauta Express blasts in which 67 Pakistani nationals died, sources said, "... there is no comparison. We have shown the will to take action, not chosen to make statements of convenience".

The sources also noted that India had managed to convict some of those involved in the Mumbai attacks through the same set of evidence which was provided to Islamabad in a trial which was not a "show trial".

Pakistan keeps switching judges, and people inside the jails are using mobile phones to run their network, the sources said, clearly expressing India's unhappiness over the slow progress of the 26/11 trial in that country.

The remarks, which were made in the backdrop of Pakistan equating the two incidents to project that it is also a victim of terrorism, also assume significance given that they come before the structured Indo-Pak talks between their Foreign Ministers in Islamabad next week