MPs from Kerala protest outside Kerala House in New Delhi after a police raid there following a complaint by a fringe group. (Press Trust of India photo)

Del police had no business to enter Kerala house. It is an attack on fed structure. Del police is acting like BJP Sena(2/2) - Arvind Kejriwal (@ArvindKejriwal) October 27, 2015

I strongly condemn what happened in Delhi at Kerala Bhavan.An unwise and unhealthy attempt to curb fundamental rights of people.Intolereance - Mamata Banerjee (@MamataOfficial) October 27, 2015

Politics over beef found a new address on Tuesday as the Kerala House in Delhi took buffalo meat off its menu after a "raid" by 20 policemen over a complaint from a fringe group.After a day of protests against what many saw as bullying, Kerala House decided to bring back buffalo meat, sending a message that reinforced Kerala Chief Minister Oommen Chandy's strong words in a letter to the Prime Minister."I would like to inform you that the Kerala House staff canteen serves authentic vegetarian and non-vegetarian Kerala cuisine and the items in the menu are entirely within law," Mr Chandy, who belongs to the Congress, wrote to PM Narendra Modi, accusing the Delhi Police of overstepping its brief.Sources told NDTV that the Prime Minister's Office has sought details of the Delhi Police action from the home ministry.On Monday evening, the official guest house of Kerala in the capital swarmed with policemen after a call from activists of the Hindu Sena group, who had visited the canteen and noticed "beef fry" scribbled in Malayalam on a handwritten menu.Defending their alacrity in responding to the complaint, the police said they acted for the sake of law and order; the Hindu Sena was involved in an ink attack last week on Jammu and Kashmir lawmaker Engineer Rashid, over his beef party in Srinagar."We know no irregularities will take place at Kerala House, but it was our duty to investigate the matter since the complaint was on a serious issue... We had no option but to react very fast, as it could have been a situation which would lead to a communal flare up," said Delhi Police chief Bassi on Tuesday evening.He added that if the Kerala House registers a complaint, "we will conduct an inquiry against the Hindu Sena men".The canteen staff explained that it serves only buffalo meat, which is not illegal, even though the term "beef" is used.Two more Chief Ministers weighed in on the controversy.Bengal Chief Minister Mamata Banerji also tweeted.Beef is at the centre of a nationwide debate after recent mob-killings over allegations of beef-eating and cow slaughter.