New Delhi  - The Indian government has information that terrorist groups in Pakistan were planning fresh attacks on Indian soil, Prime Minister Manmohan Singh said Monday.

Speaking at a conference of chief ministers in the Indian capital, Singh said there had been a surge in infiltration attempts by militants across the border with Pakistan.

"Cross-border terrorism remains the most pervasive threat," Singh said at the meeting to discuss internal security.

"There is credible information of ongoing plans by terrorist groups in Pakistan to carry out fresh attacks," Singh said. "There area of operation extends far beyond Jammu and Kashmir."

India has accused Pakistan-based Islamic militant group Lashkar-e-Taiba of planning and executing the November terrorist attack in the financial hub Mumbai in which more than 160 people were killed.

Singh also said left-wing extremism was a serious challenge to India's internal security as Maoist groups have inflicted heavy casualties on government forces in recent months.

Coordination between the federal and state governments, better information sharing and constant vigilance were essential to meet the situation, Singh said.

Federal Home Minister P Chidambaram listed terrorism, insurgency in the north-eastern region and left-wing extremism as the three big security challenges facing India.

The day-long chief ministers' conference would assess levels of preparedness to meet terrorism and other security threats, and review implementation of decisions taken so far. (dpa)