After the brazen killing of a high-profile Canadian Sikh activist in June, FBI agents visited several Sikh activists in California this summer with an alarming message: Their lives were also at risk.

The warnings have taken on a new urgency after Canada’s bombshell revelation on Monday that it has credible intelligence pointing to Indian government involvement in the assassination of Hardeep Singh Nijjar, a Canadian citizen and advocate for an independent Sikh state, who was shot dead outside a Sikh temple in British Columbia.

Pritpal Singh, a political activist and U.S. citizen who is a coordinator for the American Sikh Caucus Committee, told The Intercept that he and two other Sikh Americans involved in political organizing in California received calls and visits from the FBI after Nijjar was killed.