A team of National Investigation Agency (NIA) will today begin its probe into the Chhattisgarh Maoist attack on Congress leaders which claimed 27 lives including PCC Chief Nand Kumar Patel.

Speaking to reporters in New Delhi, Union Home Secretary R K Singh said an official order formally handing over the case to NIA to carry out the investigation would be issued soon. He also said, the NIA team will leave for Chhattisgarh today.

Home Minister Sushilkumar Shinde had earlier said the NIA will probe the Maoist attack on Congress leaders and the Centre has received a go-ahead from Chhattisgarh Chief Minister Raman Singh for it.

Mr. Shinde had also briefed Prime Minister Manmohan Singh about the decision to hand over the investigation to NIA.

Heavily-armed Maoists had on Saturday ambushed a convoy of Congress leaders in the state's Bastar district, killing 27 people including PCC chief Patel, his son Dinesh, Congress leader Mahendra Karma and ex-MLA Uday Mudliyar and injuring 32 others.

Union Minister V C Shukla injured in the attack is being treated at a Medanta hospital in Gurgaon, his condition is stated to be critical but stable.

Meanwhile, hundreds of people, with tearful eyes, are attending funerals of senior congress leaders at their native villagers.

State Congress president Nandkumar Patel and his son Dinesh are being cremated at their village Nandeli in Raigarh district, where thousands of people have gathered to have a glimpse of the leader-braving scorching heat.

State Governor Shekhar Dutt, Chief Minister Dr. Raman Singh, Congress vice-president Rahul Gandhi, Senior Congress leaders Motilal Vora, B.K. Hariprasad Madhya Pradesh state Congress president Kantilal Bhuria, leader of the opposition in MP assembly Ajay Singh are among those attending the funeral.

A sea of humanity turned out at Farasgaon in Dantewada district, where the senior tribal leader Mahendra Karma’s funeral is taking place.

Thousands of local tribals attend the last rites of Karma, who had always fought the Maoists during his long political career and earned a name among the locals as “Bastar tiger”.

Meanwhile, Chhattisgarh chief minister Raman Singh has indefinitely cancelled his on-going Vikas Yatra for highlighting the achievements of his government in the wake of the Bastar incident.

The state government has announced to an ex-gratia of Rs five lakh each to the families of those killed in the Bastar attack