Toronto, Sep 26 : Updating travel advisory for its citizens in India, Canada has asked them to "remain vigilant and exercise caution" in the wake of a diplomatic row over the killing of Khalistani leader Hardeep Singh Nijjar. "In the context of recent developments in Canada and in India, there are calls for protests and some negative sentiment towards Canada on social media. Please remain vigilant and exercise caution," the Canadian government said in an update. India had issued a similar advisory for Indian nationals and students living in Canada last week, and also announced its decision to stop all categories of visas, including e-visas, for Canadian nationals. The strongly-worded advisory said that in "view of growing anti-India activities and politically-condoned hate crimes and criminal violence in Canada, all Indian nationals there and those contemplating travel are urged to exercise utmost caution". It also advised its nationals to avoid travelling to regions and potential venues in Canada that have seen such incidents. Canada had rejected the Indian travel advisory issued by India, and said that it is one of the safest countries in the world. Recently, Punjab BJP Chief Sunil Jakhar urged the External Affairs Minister S. Jaishankar to set up a helpline for Indian students and NRIs in Canada amid rising diplomatic tension between the two countries. India is likely to cancel the registration of Overseas Citizenship of India (OCI) card holders for carrying out pro-Khalistan and anti-India activities, media reports said, citing sources. Tensions flared between India and Canada following Prime Minister Justin Trudeau's allegations that India was behind the killing of Nijjar -- a designated terrorist in India. India rejected the allegations, calling them "absurd and motivated". /IANS