As investigators grapple for leads in the Mumbai and Delhi blasts, Prime Minister Manmohan Singh on Friday said the security environment in the country was "uncertain".
Terming the terror strikes on markets in Mumbai in July and the Delhi high court on September 7 "grim reminders" of the challenges facing the country, Singh said the security establishment - too dependent on technical intelligence, such as interception of phone or internet communication - needs to improve its "human intelligence capabilities".
He was speaking at a conference of police chiefs.
Without naming Pakistan, the PM also pointed to intelligence on terror camps across the border being "reactivated" and attempts to induct militants into the country.
"There is no room for complacency," he said.
Intelligence officers said the number of militants trying to infiltrate into India by June had exceeded last year's figures. There have been more than 500 attempts so far.
The agencies were all unanimous in their assessment that the presence of militants at the 40-50 terror camps across the border has increased significantly.
On left-wing extremism, the PM said "a huge collective and coordinated effort is required by the Centre and states" to bring about a decisive change.