The 20 terrorists figure in the 'Red Book' or list of 119 'most wanted terrorists' that was drawn up by the FIA in Oct 2009 with help from provincial police forces.
They have been booked under provisions of the Anti-Terrorism Act, Pakistan Penal Code and a cyber crimes law.
However, the name of JeM chief Maulana Masood Azhar or that of the top leaders of Tehrik-e-Taliban Pakistan do not figure in the list.
Pakistani authorities have also refused to arrest LeT founder Hafiz Muhammad Saeed in connection with 26/11 attacks, saying there is no evidence against him.
This comes despite a fresh dossier that was given to Paksitan's foreign secretary Salman Bashir during his visit to India last week.