Journalists took out a march from the Press Club to the Vidhana Soudha legislature, the state secretariat, and submitted a memorandum to Chief Minister Siddaramaiah seeking immediate action to bring the culprits to book.
"We strongly believe that such silencing methods are an attempt of divisive forces in a democratic system to stifle the media," the memorandum said.
Condemning the killing, Press Club of Bengaluru president Sadashiva Shenoy said he was closely associated with Gauri Lankesh and was at loss of words to condole her death. "Divisive forces cannot muzzle the liberal voices by resorting to killing," Mr Shenoy said.
He said the Press Club of Bengaluru will form a committee to mount pressure on the government for a speedy investigation of the case.
"We demand that a judicial committee should be constituted headed by a sitting High Court judge to probe the brutal killing," Mr Shenoy said.
Freedom fighter 99-year-old HS Doreswamy led a protest at the Town Hall, where hundreds of people turned up to condole the death and express their anger against the killing of Gauri Lankesh.
Gauri Lankesh's body was kept at the Ravindra Kalakshetra in Bengaluru where mourners paid their respects.