Canadian police have detained members of an alleged hit team for their role in the assassination of Sikh activist Hardeep Singh Nijjar, the first arrests in a high-profile killing which officials believe was masterminded by India.

The arrest, first reported by CBC News, comes nearly a year after the prominent activist was killed in the parking lot of his gurdwara in the city of Surrey, British Columbia.

In September, the prime minister, Justin Trudeau, told parliament his government had “credible allegations” that India was behind the killing, calling the death of a Canadian citizen on Canadian soil an “unacceptable violation of our sovereignty”.

In the months since, the fallout from Nijjar’s murder has chilled relations between Canada and India – and exposed what officials say is a transnational campaign of violence by India, meant to target dissidents abroad.

Police are expected to brief the media later on Friday, but investigators say the group could also be tied to three other murders in Canada, including the “sick and twisted” killing of an 11-year-old boy in the city of Edmonton, according to the CBC.

Members of the group, alleged to be the gunmen and drivers responsible for the brazen 18 June killing of Nijjar, were arrested in police raids in at least two provinces.

More details soon …