New Delhi, Jan 8 (IANS) The Communist Party of India-Marxist (CPI-M) Saturday urged the government to pursue the investigation into bomb blasts blamed on "Hindutva terror groups", calling them a threat to India.

"The reported statements by Aseemananda, co-accused in a series of bomb blasts by Hindutva terrorist groups, shows that it is not just a few extremist individuals involved but a wide network which includes the involvement of top pracharaks of the RSS," the CPI-M said in a statement, referring to the Rashtriya Swayamsewak Sangh (RSS).

"Even though the investigations are belated, it is imperative there should now be no let up in nailing those responsible for the heinous terrorist crimes in Malegaon, Ajmer Sharif, Mecca Masjid and the Samjhauta train.

"The Hindutva terror groups have been spawned by the hate politics of the RSS and, as is now revealed by Aseemananda, have received direct support (from it). No effort should be spared to bring the guilty to book.

"They constitute a grave danger to the integrity and unity of our country," the statement said.