Three Sikh men and a woman convicted of carrying out a revenge attack on Lt. Gen. (retd.) K.S. Brar, the hero of the 1984 Operation Blue Star, were on Tuesday sentenced from 10-and-a-half years to 14 years in prison by a British court.

The pro-Khalistani supporters had tried to slash the throat of the 78-year-old former Indian Army officer in a revenge attack on the streets of central London in 2012 for his role in leading the operation to flush out extremists from the Sikh holy shrine of Golden Temple in Amritsar.

Barjinder Singh Sangha and Dilbagh Singh were sentenced to 14 years in prison by Southwark Crown Court in London.

Mandeep Singh Sandhu will serve 10 years and six months in prison while Harjit Kaurand will serve a 11-year-sentence.

They have to spend at least half the sentences in custody and can then be released on licence.

Sangha, 33, Sandhu, 34, Singh, 36 and Kaur, 38, were found guilty on July 31, 2013 following a trial by the same court.

Pronouncing the sentences, the judge said the “attack falls within the most serious category of wounding with intent” and took into account the “significant psychological harm caused to the Brars”.

It is clear the attack was carried out in revenge for Lt. Gen. Brar’s actions at the Golden Temple, the judge said.

During the trial, the prosecution said Kaur had tracked Lt. Gen. Brar as he holidayed in London’s West End with his wife Meena.

She then passed on the Brars’ whereabouts to the attackers.

Sangha, Sandhu and Singh were found guilty of carrying out the attack itself on September 30, 2012 and of wounding the general with intent.

Lt. Gen. Brar, giving evidence via videolink from India, said a pro-Khalistan website had declared him the “number one enemy of the Sikhs”.

Another threat he said he received read: “There have been seven attempts on his life which have not succeeded, but the eighth one will.” He was not protected on his trip to London, which he said was a private holiday.

Hundreds of Sikh men and women from across the U.K. gathered at the court for Tuesday’s hearing.