The Congress party on Saturday approached the Election Commission (EC), demanding strong action against Bharatiya Janata Party (BJP) general secretary Amit Shah for "stoking communal fire".
Campaigning in western Uttar Pradesh, Shah had recently said the 2014 elections were an opportunity to take "revenge for the insult" during the violence in Muzaffarnagar last year.
His comments evoked sharp reactions from politicians cutting across party lines, triggering a fresh row amid apprehensions that the nation might vote along the communal lines in the polls.
KC Mittal, secretary of the Congress' legal department, accused Shah of "creating animosity between communities" in the complaint to EC.
The Congress also demanded the BJP's UP-in-charge be banned from campaigning, alleging the party's prime minister nominee Narendra Modi and his aides were attempting to play the "2002 communal game" of Gujarat all over the country.
With opinion polls giving Modi an edge, political rivals have stepped up attack on him over the 2002 Gujarat riots under his watch as chief minister. The run-up to the key elections has seen debates on communalism taking centre stage in a politically charged atmosphere.
Shah, known to be an aide of Modi, had said two days ago, "In Uttar Pradesh, especially western UP, it is an election for honour. It is an election to take revenge for the insult... (and) to teach a lesson to those who have committed injustice."
He was accompanied by party legislator Suresh Rana, accused of instigating the August-September riots, in which around 61 people were killed and 50,000 were displaced.
While Arvind Kejriwal's Aam Aadmi Party (AAP) and the Janata Dal (United), too, trained guns on Shah, yoga guru and BJP sympathiser Ramdev defended him.
BJP spokesperson Mukhtar Abbas Naqvi jumped into fire-fighting, turning the heat on UP's ruling Samajwadi Party, which is on the back foot for alleged improper rehabilitation of the riot-hit victims.
"It is not a question of Hindus and Muslims. Those who went there for secular tourism have insulted the people. Instead of putting balm on the wounds of the victims, they sprinkled salt. Revenge should be taken for this insult," Naqvi said.
UP, which has the most Lok Sabha seats (80) among Indian states, is high on the agenda of the BJP. Opinion polls have predicted a good show by the saffron brigade in the state, which will see Modi contesting against Kejriwal in Varanasi.
Full coverage: Lok Sabha Elections 2014
(With inputs from PTI)