Maoist rebels ambushed police and killed 16 involved in a mine clearing operation the police said, as the insurgents demonstrated their strength ahead of a general election next month.
The victims were clearing mines laid by rebels on a road through a densely forested area in resource-rich Chhattisgarh state when the rebels attacked from all sides.
As a mark of their protest, the Congress members came out in droves in Raipur and tied black ribbons on the arms of people.
Congress party member, Vikas Upadhyay, expressed grief over the killing of many security personnel, politicians and tribals.
"Congress party has called for a shutdown in wake of the attack in which 16 security personnel were killed and in the past 10 years many young soldiers, Congress committee leaders and tribal have been killed. The people of the state have also lent their full support," said Upadhyay.
Another Congress party member, Kuldeep Juneja, demanded resignation from state chief, Raman Singh, for his inability to contain such incidents in the past.
"The chief minister should resign on human grounds, and he has no right to enjoy his position. When security personnel are unsafe, how will they protect the common man? The people have wholeheartedly extended their support and are participating in the shutdown as they are also angry," he said.
The ambush was just a few miles from where rebels killed 27 people, including many senior political leaders, before state elections last year. The attacks seek to disrupt the electoral process, the official said.