A total of 17 stab injuries were found on the body of Ramesh, doctors at the Salem Government hospital said.
52-year-old Ramesh was brutally attacked by a four-member unidentified gang while he was returning home after visiting the party office to discuss party affairs at around 9 pm on Friday night in Salem, Salem range Police DIG Sanjay Kumar said. Police said Ramesh died on the spot.
The attack on Ramesh, a chartered accountant by profession and who was also associated with the RSS, triggered protests and sporadic incidents of stone pelting in the state.
BJP demanded that the Tamil Nadu government order a judicial probe into the murder even as special police teams were formed to trace the assailants.
As a precautionary measure, authorities ordered closure of schools in Salem on Saturday.
"We want the guilty to be brought to book. We want a detailed probe into the incident by a retired judge of the Madras High Court," BJP state President Pon Radhakrishnan said.
Radhakrishnan accused the state government of not providing security to his party leaders and claimed in the last one year, three state-level leaders--Arun Reddy, P Murugan and Velliyan -- were murdered and that the culprits were still at large.
The attack was roundly condemned by BJP's national leaders with Gujarat Chief Minister and party's election campaign chief Narendra Modi and Leader of Opposition in the Lok Sabha Sushma Swaraj calling for action against the guilty.
"Killing of our Tamil Nadu unit's General Secretary V Ramesh is shocking. Spoke to TN BJP President last night and expressed sadness on the killing...The culprits must be punished at the earliest," Modi tweeted.
National spokesperson Nirmala Seetharaman said BJP leaders in the state were being attacked "one after another" in a "planned manner" which is a matter of great concern.
She demanded that the state government set up a Special Investigation Team to probe each of the attacks on party leaders in the state.
The BJP called for a day-long bandh on in Puducherry protesting the death of Ramesh.
Volunteers of different wings of BJP were arrested when they tried to picket the traffic to protest the killing.
Secretary of the party, R V Swaminathan, who addressed the volunteers, demanded the arrest of the culprits and protection to the party workers.
BJP demands SIT probe
BJP said several of its activists have been attacked and killed brutally in the recent past and demanded that a Special Investigation Team be formed to probe these cases.
"V Ramesh was brutally attacked and killed close to his home and office in Salem, Tamil Nadu. BJP condemns this attack. His murder is just one in a series, within a year, of targeted killings in Tamil Nadu," BJP spokesperson Nirmala Sitharaman said.
Arvind Reddy, state secretary, BJP Medical Cell in Tamil Nadu was killed earlier as were Murugan, an activist and former councillor and Pugazhendi, BJP district president Nagapattinam.
"BJP leaders are being attacked in a planned manner.... It is apparent that all these attacks are undertaken with detailed planning and after surveillance of the movements of these activists. Each of these attacks has been gruesome and brutal," Sitharaman said.
BJP maintained these killings are aimed at instilling fear in the minds of the people.
The main opposition pointed out that during senior BJP leader L K Advani's yatra in 2011, a plan was hatched to kill him with a pipe bomb in Tamil Nadu.
"This dangerous drift towards political attacks and killings should be stopped instantly. The Tamil Nadu government should set up a high-level Special Investigation Team to thoroughly investigate each one these attacks," Sitharaman said.
BJP demanded protection for its party members who are under threat.