"As a society, there is no place for violence," he said while getting emotional at the Sabarmati Ashram in Ahmedabad.
"Killing people in the name of 'gau bhakti' (cow worship) is not acceptable. This is not something Mahatma Gandhi would approve," he said.
Modi said "as a society, there is no place for violence."
"No person in this nation has the right to take the law in his or her own hands in this country," he added.
Violence never has and never will solve any problem, he said.
Modi urged all to work together. "Let's create the India of Mahatma Gandhi's dreams. Let's create an India our freedom fighters would be proud of."
This is not for the first time he has spoken on cow vigilantism.
" "Kabhi kabhi ye jo gau raksha ke naam par kuch log apni dukaane khol kar baith gaye hain, mujhey itna gussa ata hai (Some people have been running a business the name of gau raksha. I feel so angry)," he said in August last year.
"I have seen that some people who indulge in antisocial activities through the night put on robes of gau rakshaks by day," he added.
Earlier this week, a Muslim dairy farmer was severely injured after a mob charged at his residence amid rumours of a cow carcass being found outside his home in Jharkhand’s Giridih district.
The shocking incident comes close on the heels of another incident in which a 15-year-old Junaid Khan was stabbed to death in a crowded delhi-Mathura train. The fight over seats turned communal as attackers accused Junaid and his brothers of consuming beef and being anti-national.
A 50-year-old Delhi government employee was among four persons arrested yesterday in connection with the killing of Junaid.
With the four arrests made yesterday, the number of those held in the case has climbed to five, according to Government Railway Police, Faridabad, SP, Kamaldeep Goel told news agency PTI.
However, the "prime accused" was still at large, he said.
Here are other important things PM talked about:
Killing people in the name of Gau Bhakti is not acceptable. This is not something Mahatma Gandhi would approve: PM
- As a society, there is no place for violence: PM
- We are a land of non violence. We are the land of Mahatma Gandhi. Why do we forget that: PM
- Today I want to say a few words and express sadness on some of the things going on: PM
- Swachhata has to become a Swabhav. What can be a greater tribute to Mahatma Gandhi than this: PM
- I urge people from all over to come and visit the Sabarmati Ashram: PM
- There should be further academic research on the life and thoughts of Shrimad Rajchandraji: PM
- The thoughts of Mahatma Gandhi have the power to mitigate the challenges the world is facing today: PM
- As a society, it is always essential to remain connected with our history: PM
- This year we mark the 100th year of the establishment of Sabarmati Ashram as well as the Champaran Satyagraha: PM
Modi is on a two-day visit to Gujarat from Thursday and will launch some projects and attend various
programmes, including a Textile Summit and a roadshow.
This will be Modi's fourth visit this year to his home state where Assembly elections are due by the end of the year. Interestingly, fourteenth legislative assembly election will be held in 2017 to elect members of the 182 constituencies in Gujarat.