New Delhi, Apr 16 (IANS): Expressing concern over the growing number of domestic terror outfits, union Home Minister P. Chidambaram Monday appealed to states to join in countering such outfits.

Speaking at the annual conference of chief ministers on internal security, Chidambaram said that in the two major attacks of 2011 - the serial blasts of July in Mumbai and the blast near Delhi High Court in September - the arrested suspects were Indians.

"The chilling facts are principal suspects in two cases are Indian nationals... They operated across states, many of them had no previous criminal records," Chidambaram said.

"I have to conclude regretfully that thanks to radicalisation, there are many Indian groups, which have acquired the capacity to carry out terror attacks," he said.

The home minister informed the conference that in 2011 18 domestic terror modules were neutralised and 53 people were arrested, and in 2012 so far three modules were neutralised and 11 people were arrested.

He said the state police and central agencies worked together in cracking these cases, and lauded their efforts. The home minister also expressed concern over the support being extended to those arrested by some groups.

"The cause of worry, however, in practically every case, is a small group of people spring to support of people who are detained for interrogation, or arrested for charge... There is no reason for such support except the affinity of religion or sect," he said.

"...this is a dangerous trend and makes the task of investigation agency more difficult," said Chidambaram.

He also urged the states to join in discouraging such practices.

"I would request you to join me in appealing to the people and to the media to observe caution and restraint and place faith in the integrity and impartiality of investigation," he added.