David Cameron became the first serving British prime minister to visit the scene of a 1919 massacre in India, one of the bloodiest events in Britain’s colonial past.

During his appearance at the Jallianwala Bagh, Amritsar, in the northwestern Indian state of Punjab -- the site where hundreds of civilians including women and children were shot dead by British troops on April 13, 1919 -- Cameron said the massacre was "a deeply shameful event in British history."

"[It was] one that Winston Churchill rightly described at the time as monstrous,” Cameron wrote in the memorial book of condolences. “We must never forget what happened here. And in remembering, we must ensure that the United Kingdom stands up for the right to peaceful protest anywhere in the world."

Cameron, bare-footed and wearing a blue bandana to cover his head to honor the Sikh religious tradition, said: “In coming here to Amritsar, we should celebrate the immense contribution that people from the Punjab play in Britain, the role they play, what they give to our country,” the BBC reported.

Though there were some calls for the prime minister to issue a formal apology for the killings, he stopped short of doing so.

Previous British leaders have addressed the Amritsar atrocity, without explicitly apologizing for it.

As war secretary in 1920, Churchill described the shootings as “a monstrous event, an event which stands in singular and sinister isolation.”

Before he became prime minister, Tony Blair said the memorial at Amritsar was a reminder of “the worst aspects of colonialism.”

Queen Elizabeth II visited Amritsar in October 1997 and acknowledged that the shooting was a “distressing episode in history.” However, her husband, Prince Philip, kicked up a massive controversy by saying that the death toll of the shooting had been "vastly exaggerated."

Indeed, the death toll has long been disputed with an inquiry set up by the colonial authorities placing the figure at 379, while Indian sources say it is much higher and nearer to 1,000.

Cameron’s trip to Amritsar came at the end of his three-day visit to India that focused heavily on the potential for increased Indo-British ties, particularly in trade, arms and business collaborations.

His talks with his Indian counterpart Manmohan Singh Tuesday were overshadowed by India’s concerns about allegations of corruption over a $752-million helicopter deal with the Anglo-Italian firm AgustaWestland.

India’s defense ministry has suspended payments for 12 helicopters until India's Central Bureau of Investigation (CBI) completed an investigation.

During the talks, which included topics such as nuclear energy cooperation, security, terrorism and trade, Singh conveyed India's “serious concerns” over the chopper scam and sought Cameron's  “full assistance” on the issue, Outlook India reported.

Cameron said the British government would respond to “any requests for information” regarding AgustaWestland, adding: “I am glad the Italian authorities are looking into this issue in detail as Finmeccanica is an Italian company, a parent company of AgustaWestland."

Cameron also voiced support for India's full membership in the Nuclear Suppliers Group and other multilateral export control regimes and expressed willingness to "rewrite" the rules on sharing technology in a bid to increase high-tech exports.  The discussions detailed defense and security cooperation, including in the field of cyber security.