After being summoned by Governor P Sathasivam, Chief Minister Pinarayi Vijayan promised that action would be taken against law-breakers irrespective of their status and political affiliation. Union Home Minister Rajnath Singh also told him to curb political violence.
The Bharatiya Janata Party called the shutdown after E Rajesh, 34, a member of the Rashtriya Swayamsewak Sangh (RSS), was hacked to death here on Saturday night. He died a few hours later.
All shops and markets across the state were shut and all public vehicles went off the roads, residents and officials said. The few private vehicles which plied faced angry BJP and RSS activists.
Kerala Police chief Loknath Behra told reporters that all but one of those involved in the crime has been arrested.
"Their questioning has started. Preliminary indications are that there was political and also personal rivalry," he said.
In another unprecedented development, the Governor, a former Supreme Court Chief Justice, summoned Vijayan and Behra to know the law and order situation in the state.
In the last two weeks, there was an attack on the state BJP headquarters and the residence of the son of CPI-M State Secretary Kodiyeri Balakrishnan before Rajesh was murdered.
Sathasivam quoted Vijayan as saying that he would meet both state BJP President Kummanam Rajasekharan and the state RSS chief and make a public appeal for peace.
Earlier, Sathasivam spoke on the phone with Rajnath Singh, who in turn asked Vijayan to curb political violence in the state. The Governor also spoke to BJP's Rajasekharan and CPI-M's Balakrishnan.
Police arrested all the five persons who took part in the hacking of Rajesh and three others who helped them. One man is on the run.
The arrests took place from a rubber estate in the capital's suburbs.
Balakrishnan told reporters here that the CPI-M had no role in the RSS man's murder.
Rajnath Singh tweeted: "I have expressed my concern about the law and order situation in the state. Political violence is unacceptable in a democracy. I expect the political violence in Kerala is curbed and the perpetrators are brought to justice expeditiously."
Hundreds of people were stranded at railway stations and bus terminals. A family which travelled from Thiruvananthapuram to Kochi, 250 km away, said it underwent a nightmare.
"At several places supporters of RSS and BJP stopped us and spoke as if we were criminals. Finally, after a lot of trouble, we reached Kochi," businessman Ajith Kumar told IANS.
A funeral that was to take place on Sunday was postponed for Monday as many people could not make it, K. Thomas of Puthupally in Kottayam district told IANS.
Rajesh's body, after an autopsy, was taken in a procession to his house near here. En route, the BJP and RSS workers damaged the flag posts of the CPI-M.