Prime Minister Manmohan Singh and Congress chief Sonia Gandhi Sunday met victims of the Chhattisgarh Maoist attack, which left at least 16 dead, including two senior Congress leaders, and 25 people injured.
Both the prime minister and the Congress chief visited the hospital in Raipur where the injured have been admitted, and interacted with members of victims' families.
"This is a black day for democracy, this will harm grassroots politics," the Prime Minister's Office later quoted Manmohan Singh as saying in conversation with a victim in the hospital.
Both the leaders will also be meeting party workers in state capital Raipur.
Congress vice president Rahul Gandhi has been camping in Raipur since late Saturday after tye news of the attack came in.
A large number of Maoists Saturday attacked a Congress party convoy, blocking its way with felled trees, setting off a landmine blast and then opening fire.