Cameron’s visit to the Amritsar massacre site to pay respects makes him the first British prime minister since India’s independence to do so.

According to reports in India, Cameron wrote in the visitors’ book at the massacre site that it was a “shameful act in British history”

“We must never forget what happened here.” He added.

The April 13, 1919 Jallianwala Bagh massacre took place when Dyer ordered fire without warning on the 15,000 Indian protesters who gathered to demonstrate against the British rule. The shooting killed more than 1000 Indians according to the Indian officials then.

Cameron laid a wreath at the Amritsar massacre memorial, bowed and stood in silence to pay his respects.

Dyer’s orders and the killings were condemned by Winston Churchill in 1920 who described the act as "monstrous".

“We must ensure that the UK stands up for the right of peaceful protests,” Cameron is quoted as saying by the Indian media.

The British Prime minister also visited the Golden Temple in Amritsar, the holiest shrine for those following the Sikh religion such as the Indian Prime Minister Manmohan Singh.

Previously Prime Minister Tony Blair expressed regret over the Jallianwala Bagh massacre but Cameron has become the first UK PM to visit the site in person to pay his respects.

Cameron is in India on a three-day state visit aiming to bolster trade, investment and bilateral relations. He wants to o forge one of the “great partnerships” of the 21st century with India, he said ahead of the visit.

During his three-day schedule, UK and India struck several trade and investment agreement, the UK launched a super priority visa service for frequent Indian visitors, the London School of Economics launched scholarships for Indian students and Cameron pledged full support for India’s investigation into Anglo-Italian company AgustaWestland’s chopper contract.