1978 Sikh–Nirankari clashes

On 13 April 1978, a violent incident happened between the Sant Nirankari Mission and traditional Sikhs. This was at Amritsar, Punjab, India. Sixteen people were killed.
This incident eventually led to Operation Blue Star and the Punjab insurgency in the 1980s. Clashes occurred when Akhand Kirtani Jatha and Damdami Taksal members led by Fauja Singh protested against and tried to stop a convention of Sant Nirankari Mission followers. This incident is considered to be a starting point in the events leading to Operation Blue Star and the 1980s insurgency in Punjab. 
The turning point in the Sikh-Nirankari relationship is believed to have come after Avtar Singh took over as the sect chief in 1943. He not only proclaimed himself “Satguru” but also introduced a book “Avtar Bani” and allegedly tried to copy Sikh symbols like starting the system of Sat Piare etc. He was successful in organising Nirankaris into a powerful sect. However, in his book “A History of The Sikhs”, Khushwant Singh noted that the fundamental difference between both was that the Nirankaris were worshiping gurus other than the 10 recognised by the Sikhs.
However, the conflict reached its peak on April 13, 1978. Activists of the Akhand Kirtni Jatha and Damdai Taksal marched towards the venue of a Nirankari convention in Amritsar. It led to a clash that left at least 17 dead and a majority of them were Sikhs.
Following the deadly clash in 1978, Akal Takht issued a hukamnama asking Sikhs to sever ties with Nirankari Sikhs. Later in 1980 in Delhi, Akhand Kirtani Jatha’s Ranjit Singh killed Nirankari chief Gurbachan Singh. Ranjit Singh was later nominated as Akal Takht Jathedar.