Hawzah News Agency (New Delhi, India) - Carrying placards saying "Not in my name," the protesters decried the silence of the Hindu nationalist government in response to public lynchings and attacks on at least a dozen Muslim men and boys since it took power in 2014.
Pratap Bhanu Mehta, a leading commentator, this week described the lynching’s as "a protracted riot in slow motion."
"What makes this violence chilling ... is that it is acquiring an atmosphere of a religious communion about it," he wrote in the Indian Express.
Anjali Arondekar, a professor, visiting from California, said she had attended the Mumbai protest because "nobody seems to care anymore that a young Muslim man is being killed."
In New Delhi, thousands of people, including the elderly and parents with young children, sang songs and lit candles. In Mumbai, hundreds, including some Bollywood actors, gathered under umbrellas in the pouring rain.
Protests were also reported in several other cities. Last Friday, about 20 men attacked four Muslims on a train in the outskirts of New Delhi, fatally stabbing a teenager and seriously injuring two others. On Tuesday, a man was beaten and his house set on fire by a mob that accused him of slaughtering a cow in eastern Jharkhand state.
"I feel afraid. I don't even know if I will be able to reach home safely," Bashruddin Khandawali, a 24-year-old cousin of Junaid Khan, who was killed last week on the train, told Reuters next to a huge "Lynch Map of India" banner.
The Muslim men said an argument over seats quickly turned into a brutal attack, with the mob accusing them of being "beef-eaters." Many members of the Hindu majority consider cows sacred. The slaughter of cows and eating of beef is illegal or restricted across much of India.
Much of the recent violence has been focused on cows. Several fringe Hindu groups, apparently emboldened by the stunning political rise of Prime Minister Narendra Modi's Bharatiya Janata Party, have attacked Muslim cattle traders and dairy farmers.
Muslims constitute about 14 percent of India's 1.3 billion people, while Hindus comprise 80 percent.
Rights groups say government officials, including the prime minister, have been slow to strongly condemn the attacks and that police action against perpetrators have been inadequate.
Five of the killings, almost all of them in broad daylight and in busy public areas, have taken place in the last three months.
On April 1, Pehlu Khan, a Muslim cattle trader, was lynched by a mob in the western state of Rajasthan as he transported cattle he had purchased at an animal fair to his home state of Haryana. Khan and his family were small dairy farmers.
In May, two Muslim men were beaten to death over allegations of cattle theft in India's northeast.
Critics accuse right-wing Hindu groups, some linked to Modi's party, of fomenting or not doing enough to stop violence against Muslims and lower-caste Hindus who eat beef or work in the meat and leather industries.
Modi denies the accusation and has publicly criticized so-called cow vigilantes. Many Hindus worship the cow as sacred to their religion.
Almost all of the 63 attacks since 2010 involving cow-related violence were recorded after Modi and his Hindu nationalist government came to power in 2014, IndiaSpend, a data journalism website, said in a report.
Twenty-eight Indians 24 of them Muslims have been killed and 124 injured since 2010 in cow-related violence, IndiaSpend said.
India's history is pockmarked by Hindu-Muslim communal clashes, although the vast majority of people live peacefully together.
Over the last two years, vigilante groups, who call themselves cow protectors, have become active in small towns and cities across India. Even lower-caste Hindus who carry out undesirable tasks such as skinning dead cattle have faced mob violence.