The Bharatiya Janata Party (BJP) was in the line of fire on Monday over senior leader Amit Shah's remark that Azamgarh in Uttar Pradesh was a "base of terrorists".
Congress leader Digvijaya Singh accused Shah and BJP's prime ministerial nominee Narendra Modi of practising "communal" politics.
UP chief minister Akhilesh Yadav requested the Election Commission (EC) to take action against Shah, who was pulled up by the poll watchdog last month following complaints over his alleged hate speech in riot-hit Muzaffarnagar.
Bahujan Samaj Party (BSP) chief Mayawati, too, requested the EC to ban his campaigns in UP.
At a rally in Azamgarh a day ago, Shah, the BJP's UP-in-charge, had alleged the area was a haven for terrorists as there was no fear of the state government, "which is advocating their release".
Reacting to the controversial BJP leader's remarks, Mayawati called for enhanced security in the constituencies where polling is to be held over the last two phases on May 7 and 12.
Thirty-three of the 80 seats in the state are yet to vote. Polling in Azamgarh, where Mayawati's rival and ruling Samajwadi Party (SP) chief Mulayam Singh Yadav is pitted against BJP's Ramakant Yadav, will he held on May 12.
Mulayam's son and CM Akhilesh Yadav said, "The Election Commission must take note of this. He has just apologised. Now again, he has made such comments. Ever since he became the BJP's UP in-charge, he has been trying to divide the people in the state."
Shah had landed in the eye of the storm after allegedly asking voters to take revenge, ahead of polling in riot-hit Muzaffarnagar in western UP.
The EC had imposed a ban on his campaigns in the state. The order was revoked after Shah told the commission that he would not anymore use derogatory or abusive language.
Following the fresh controversy in a polarised election season, Congress general secretary Digvijaya Singh alleged Modi and his aide Shah were banking on a "communal campaign".
He wrote on micro-blogging site Twitter, "Modi and Amit Shah have come back to communal campaign from development. They have forgotten involvement of Sanghi activists in Modasa bomb blast (in 2008)."
He added, "Modasa is in Gujarat. Azamgarh has been a symbol of Hindu-Muslim amity. It didn't have any riots in (19)47 and (19)92 post Babri Masjid demolition. I strongly condemn Amit Shah's statement about Azamgarh. Election Commission must take action."
Attacking Modi, he asked the Gujarat chief minister to speak out on grants given by the Gujarat government to NGOs run by Aseemanand and Pragya Singh, both accused in bomb blast cases.
Aseemanand is an accused in 2007 Samjhauta Express blast case while Pragya Thakur is a key accused in 2008 Malegaon blast case.