Terming the escalation of violence in Nandigram as 'dicey and tricky,' the Central government on Sunday said it was a matter of deep concern for both the Centre and West Bengal government, and the entry of Maoists in the scene had aggravated the problem.

"I think, Delhi is concerned, West Bengal is also deeply concerned. We have to ensure that more lives are not lost," National Security Advisor M K Narayanan, who is accompanying Prime Minister Manmohan Singh [Images] to Moscow [Images], told media persons.

He said Nandigram is an area where Maoists have made an entry and some of the violence there could be attributed to them.

Narayanan said the prime minister was directly in touch with Home Minister Shivraj Patil and was monitoring developments in the trouble-torn areas.

Patil has also spoken to West Bengal Chief Minister Buddhadeb Bhattacharya on more than one occasion in this regard.

Narayanan said a senior officer had been sent to Nandigram to report back, which will help in deciding what more steps are needed to be taken.