Gandhi also conveyed his condolences to the family of the slain youth Congress leader TH Shuhaib.
"I'm shocked to hear about the murder of Kerala AYC General Secretary, T H Shuhaib. I hope the perpetrators of this cowardly act are brought to justice soon. My condolences to his family. May his soul rest in peace," the Congress president tweeted.
Youth Congress leader and Mattanur party Block Secretary Shuhaib was hacked to death allegedly by CPI(M) workers in Kannur district.
Congress Working Committee member and former defence minister A K Antony said the killing of Shuhaib was the latest episode of "red terror" unleashed by ruling the CPI(M).