Prime Minister Justin Trudeau says he will offer a full apology for the 1914 Komagata Maru incident, in which hundreds of migrants from India were denied entry to Canada.

Trudeau made the announcement at the Vaisakhi Celebration on Parliament Hill Monday.

The Komagata Maru was a chartered ship that sailed into the Vancouver harbour on May 23, 1914, with 376 people from Punjab, India on board. Most of them were Sikh men.

The Canadian government refused to allow the passengers to disembark and the ship sat in the harbour for two months. The ship was eventually sent back to India, where 20 people were killed as they tried to disembark. Others were jailed.

“The passengers of Komagata Maru, like millions of immigrants since, were seeking refuge and a better lives for their families,” Trudeau said Monday. “With so much to contribute to their new home, they chose Canada and we failed them utterly.

“As a nation, we should never forget the prejudice suffered by the Sikh community by the hands of the Canadian government of the day. We should not and we will not,” he added.

“That is why next month, on May 18th, I will stand in the House of Commons and offer a full apology for the Komagata Maru incident.”

The announcement was described as “very meaningful” and possibly a small surprise to the Sikh and Punjabi communities, according to a Sikh leader.

“I think the community was pleasantly surprised; I don’t think anyone saw this coming to be honest,” Jaskaran Sandhu, a board member of the World Sikh Organization, told CTV News Channel Monday. “It has a lot of symbolic value for everyone.”

Trudeau’s gesture helps bring awareness to the tragedy, which Sandhu said was once considered “more or less a footnote” in Canadian history.

“I think it’s a testament to how far we’ve come in Canada, where we can go from something that was so discriminatory, so destructive, to where we have now … a strong multicultural and pluralistic community,” Sandhu said.

Former prime minister Stephen Harper apologized for the incident in a 2008 speech in Surrey, B.C., but his apology was rejected by many members of the Sikh community who said they wanted it delivered in the House of Commons.

Defence Minister Harjit Sajjan, who was the first Sikh-Canadian to command a Canadian army reserve regiment, tweeted Monday that he is “truly honoured” by Trudeau’s commitment to a formal apology.