Rekha Kadiresh, 46, was rushed to the Kempe Gowda Institute of Medical Sciences (KIMS) but could not be saved, police said, adding that previous enmity was suspected to be the reason behind the murder.
According to the Additional Commissioner of Police S Murughan, Rekha was distributing food kits when the two motorcycle-borne youths attacked her at around 10.30 AM.
"Our investigations are in full swing. Very soon we will arrest the culprits," Murugan told reporters.
Police sources said the two CCTV cameras installed in front of her house were found to be turned in the opposite direction in a manner that nothing happening on the street could be captured.
Her husband Kadiresh had been stabbed to death by two youths on February 7, 2018.
His assassins had later surrendered before a city court.
According to the party office-bearers, Rekha had represented Chalavadipalya ward once -- from 2015 to 2020.
Reacting to the incident, Chief Minister B S Yediyurappa said he has spoken to the Bengaluru police Commissioner Kamal Pant.
"Earlier her husband too was murdered brutally. We will take stringent action and will arrest the murderers within 24 hours," Yediyurappa said.
The incident took a political twist with BJP leader and former councillor N R Ramesh alleging that no one was safe in Chamarajpet assembly constituency (where the attack took place) which is represented by the Congress MLA B Z Zameer Ahmed Khan.
"I will not get into details," said Ramesh, who claimed that the party had decided to field Rekha again in the coming BBMP elections.
Denouncing the charge, Khan said it was a matter of shame that such allegations were leveled.
"It''s a failure of the BJP government which could not prevent this killing. The deceased was like my sister. She might have been in a different political party but we were like a family as we used to work together for the development of our constituency," Khan said.