NEW DELHI -- The UK's refusal to recognize the Indian-made version of the AstraZeneca vaccine has triggered a firestorm of protests in India, BBC reported.

With more than 721 million doses administered so far, Covishield is India's most widely used vaccine.

In July, even the UK received five million doses of the jab from India.

India has described the move as "discriminatory" and asked the UK to stop requiring fully-vaccinated Indians to self-isolate for 10 days on arrival.

At the moment, fully-vaccinated Indians traveling to Britain have to abide by this rule, as well as book and take Covid-19 tests before they are allowed to move freely.

Last week, the UK announced new rules -- which will come into effect on 4 October -- which mandate that travelers from a number of countries arriving in England do not have to self-isolate if they are fully vaccinated.

But Indians are not included in that list, which means that even those with two doses will be considered "not vaccinated" and will still have to self-isolate.

This is despite the fact that AstraZeneca's Covishield is among four vaccines listed by the UK.

Prominent Indians have called the rule "highly discriminatory", "racist" and "asinine", among other things.

Foreign Minister S Jaishankar has taken up the matter "strongly" with his UK counterpart Liz Truss, according to India's foreign secretary Harsh Vardhan Shringla.

It is "a discriminatory policy and does impact our citizens traveling to the UK", Mr Shringla told reporters. He warned that India might take "reciprocal measures" if the UK did not address India's concerns. Such measures generally include India imposing similar restrictions on those arriving from Britain.

A leading MP from the main opposition Congress party, Jairam Ramesh, tweeted that the "bizarre" decision "smacked of racism".