Modi, who has been fighting hard to erase the taint of the 2002 communal riots, was recently elevated as chief of the BJP's election campaign committee and his greetings to the Muslims is being seen as part of his image makeover ahead of the 2014 Lok Sabha elections.
Reacting to Modi's tweet, Gujarat Congress president Arjun Modhwadia, without naming any party or individual, said, "They will do anything to get votes."
"They will rake up the Ram temple issue and then drop it. They will say that Mohammed Ali Jinnah was secular. They will burn Sachar committee report and they will extend greetings on Ramzan."
"Yeh janata hai, yeh sab jaanti hai (the public knows everything)," he added.
Modhwadia also took to Twitter to extend Ramzan greetings, saying "Ramzan Mubarak to everyone. May this holy month bring peace and prosperity to all."