Singapore called in India's envoy Wednesday to protest "unfounded" claims by New Delhi's chief minister that a coronavirus strain from the city-state was dangerous for children.

India is suffering one of the world's worst Covid-19 outbreaks while tiny Singapore has been praised for keeping the disease in check with relatively few infections.

But following a slight uptick in Singapore, Delhi chief minister Arvind Kejriwal tweeted a warning about a "new coronavirus strain" from the city-state that is "extremely dangerous for children", and urged the government to impose a flight ban.

Singapore's foreign ministry said it had expressed concerns to India's high commissioner in the city-state about the chief minister's "unfounded assertions".

The ministry said it was "disappointed that a prominent political figure had failed to ascertain the facts before making such claims", adding there was no "Singapore variant".

The strain detected in many recent cases in Singapore was the one first seen in India, it added.

Kejriwal's comments also invited the wrath of the Indian government, which said he had no authority to speak on such matters.

"Irresponsible comments from those who should know better can damage long-standing partnerships," foreign minister Subrahmanyam Jaishankar tweeted.

"So, let me clarify -- Delhi CM does not speak for India."

A foreign ministry spokesman said India's high commissioner had clarified to Singapore that Kejriwal "had no competence to pronounce on Covid variants or civil aviation policy".

Kejriwal is a member of the Aam Aadmi Party, a rival to India's ruling Bharatiya Janata Party.