Congress leader Digvijay Singh on Thursday expressed regret over causing 'embarrassment' to the party and the government with his newspaper article on Naxal menace in which he had criticised Home Minister P Chidambaram's handling of the issue.

"He (Chidambaram) has been my friend for a long time and still remains so. The timing of the write-up was such that the government and the party both faced embarrassment for which I express regret," the All India Congress Committee general secretary in charge of Uttar Pradesh told reporters.

In a strongly-worded article in a leading newspaper, Singh had earlier in April questioned Chidambaram's strategy of treating the Naxal issue as a law and order problem and described the minister as 'extremely rigid' having 'intellectual arrogance'.

The party had quickly distanced itself from the comments.

Singh today said that there were several details regarding "the failure of the Chattisgarh police and its intelligence in Dantewada leading to the Dantewada tragedy as well as the unholy nexus between some Bharatiya Janata Party leaders and Naxalites" in the article.

"Unfortunately, the media highlighted only the part which referred to Home Minister P Chidambaram," he said.

To a question on Maoist idealogue Tusharkant Bhattacharya, who is presently in jail, Singh said he knew Tusharkant but would not elaborate as it was a 'sensitive issue'.