Tension prevailed in many parts of Karnataka over the killing of Praveen Nettaru, a member of the BJP's youth wing, Bharatiya Janata Yuva Morcha.
According to police, the motorcycle-borne killers attacked Praveen and reportedly fled to Kerala.
The state government formed six police teams to track down the killers and 15 people have been taken into custody for questioning. Three teams have been sent to neighbouring Kerala and Karnataka districts of Kodagu and Hassan.
Meanwhile, the Hindu body Vishwa Hindu Parishad (VHP) has called for a bandh even as hundreds joined in as his body was taken to his home. Some right-wing outfits have alleged that the Popular Front of India (PFI) and Social Democratic Party of India (SDFI) were behind Praveen's murder.
District police chief Rushikesh Sonanay has said, "three assailants had come on a bike. We have information that the bike had a Kerala registration number. We are scanning CCTV footage for clues," he added.
Notably, restrictions on public gatherings have been imposed in the Dakshina Kannada district.
Angered by the killing, many youth wing members of the BJP across the state started mass resignations from the outfit, saying that the BJP-led state government had failed to protect the lives of party workers. Visuals of protesters surrounding state BJP president Nalin Kumar Kateel's car and heckling him have gone viral.
Chief Minister Basavaraj S Bommai has strongly condemned the attack and assured a speedy investigation. He has said those behind the heinous act will be arrested soon and punished as per law.
Home Minister Araga Jnanendra said the crime spot is close to the Kerala border and police are in touch with the neighbouring state's police to make headway in the probe.
"It is natural that there will be anger over losing a young man, but I request people to maintain peace," the home minister said.
Security has been stepped up in Udupi and Dakshina Kannada districts.
Praveen had recently made a Facebook post in support of Kanhaiyalal, the tailor who was beheaded in Rajasthan’s Udaipur last month for supporting sacked BJP spokesperson Nupur Sharma.
In the June 29 post, Praveen had written about a “poor tailor” being beheaded, and threats to Prime Minister Narendra Modi by the killers.
He had also attacked the Congress, which is in power in Rajasthan.