The Centre has found it "intriguing" that no action was taken by the Chhattisgarh government on its specific alert about a huge presence of armed Maoists in Bastar area, where 27 people were killed on May 25, as the Congress decided to make the massacre a poll issue.
As HT wrote on May 27, the Centre had alerted the state that around "200 armed Maoists" had gathered on the Bastar-Sukma border for an 'area-domination exercise'.
A section of Congress leadership, including its state chief, in Chhattisgarh was wiped out when in an audacious attack hundreds of armed Maoists ambushed a Congress convoy in Sukma district of Bastar division.
The Congress leaders were returning from a rally as part of the party's Parivartan Yatra in the run-up to the assembly polls due in October.
The massacre looks to have been brought on by security lapses at multiple levels.
A blame game is on over the alleged security lapses.
The Congress has accused the ruling BJP of failing to provide adequate security to its leaders despite specific alerts.
The Congress leaders were told about the Maoist threat in the area, chief minister Raman Singh said.
Both Prime Minister Manmohan Singh and Congress president Sonia Gandhi are understood to have expressed serious concern over the "security failure".
It is also learnt that the state government had to be persuaded into allowing a National Investigation Agency probe. The anti-terror body has registered an FIR and launched a probe.
"It is a horrendous incident…on a scale not known before," the sources said, adding it was too early to jump to any conclusion.
The investigations would cover all aspects, including whether the standard operating procedure was flouted, said sources.
With state polls a few months away, the Centre has warned of more such attacks and asked the state to coordinate the movement of political leaders.
The Congress has been forced to rethink its strategy to fight the red menace.
The first such indication came from rural development minister Jairam Ramesh, a strong votary of development supported by political activity to tackle Naxalism, who called for a pro-active security action to deal with the Maoists.
Despite the setback, the Congress will go ahead with its campaign programme.
It will look to gain sympathy votes by drawing voters' attention to the killings -- a move that is likely to give some anxious moments to the BJP, which is serving its second consecutive term in the state.
Congress vice-president Rahul Gandhi will be monitoring the situation on daily basis.