Indian police said Wednesday they had arrested six people after a 50-year-old Muslim man was beaten to death over rumours he had eaten beef, a taboo in the Hindu-majority nation.
Mohammad Akhlaq was dragged from his house on the outskirts of the capital and attacked by around 100 people on Monday night, a police officer told AFP.
"When our team reached the spot a crowd was there outside his house. They (police) managed to rescue him and take him to the hospital, but his life could not be saved," said senior police superintendent Kiran S.
"We have arrested six people and deployed additional personnel to contain any further repercussions."
Akhlaq's 22-year-old son was also seriously injured in the attack and was in intensive care at a nearby hospital.
Killing cows is banned in many states of India, a majority-Hindu country that also has sizeable Muslim, Christian and Buddhist minorities.
In March, the state of Maharashtra toughened its ban to make even possessing beef illegal, a move seen by religious minorities as a sign of the growing power of hardline Hindus since nationalist Prime Minister Narendra Modi came to power.
The rumours that the family had eaten been began when a calf was reported missing in Dadri village, 35 kilometres (22 miles) from New Delhi.
"An announcement about the family consuming beef was made at a temple, after which the mob descended on the man's house," said Kiran.
The Indian Express quoted Akhlaq's daughter Sajida as saying the family had mutton in the fridge and not beef.
"They accused us of keeping cow meat, broke down our doors and started beating my father and brother. My father was dragged outside and beaten with bricks," she told the daily.