NEW DELHI — A sharp rise in Covid-19 cases in India over the past week has sparked fears that a third wave, driven by Omicron, is around the corner, BBC reported.

The country reported 16,764 new infections and 220 deaths on Friday for the last 24 hours.

This is the highest single-day increase in cases since October.

The jump appears to be the starkest in densely packed metros such as the national capital, Delhi, financial hub Mumbai and Kolkata city.

Mumbai reported 3,671 new cases on Friday, up 46% from the previous daily total - cases in Delhi (1,313) were up by 42%, and in Kolkata (1,090) by 102% in just 48 hours.

India experienced a devastating second wave in April and May, with daily averages of around 400,000 cases at the peak of the crisis. Caseloads dropped significantly since then - for many months the national tally remained well under 10,000 cases a day.

But officials and experts fear that the new highly transmissible Omicron variant is starting to fuel a third wave.

It accounted for 309 fresh infections on Friday - taking the total number of Omicron cases in India to 1,270 cases. Maharasthra state, where Mumbai is located, has reported the highest Omicron cases (450) so far, followed by Delhi (320).

The variant, which was first discovered in South Africa in November, has since spread fast across the world, dampening Christmas and New Year celebrations.

Many countries, including India, have imposed travel restrictions after the World Health Organization (WHO) designated it a variant of concern.

Preliminary studies published in the UK and South Africa suggest that fewer people infected with Omicron need hospital treatment when compared with other variants.

But experts still advise caution as the infectious nature of the variant could lead to a surge in cases, increasing the load on already strained healthcare systems.

"In India, we may not see a surge in intensive care unit (ICU) admissions, unlike the second wave. But there could be an increase in people who need to be hospitalised, even if it is just for monitoring," says Dr A Fathahudeen, who heads the pulmonary and critical care department at Ernakulam Medical College in southern India.

He points to three worrying factors: the number of Indians who are yet to be vaccinated, high levels of chronic disease and the proportion of elderly people in the population.

India has partially vaccinated almost 90% of its eligible population till now, but that still leaves close to 100 million adults who haven't received a single dose of the vaccine.

Millions of Indians also have comorbidities - conditions such as diabetes, high blood pressure and obesity - which makes them more vulnerable to severe illness if they get infected.

During the second wave, a sharp surge in cases overwhelmed the country's healthcare system. Hospitals ran out of beds, critical medicines and medical oxygen - relatives of patients were forced to turn to the black market or appeal for help on social media.

The country is unlikely to see that scale of damage this time, says Dr Chandrakant Lahariya, a public policy and health systems expert.

"There is limited probability that we will see the same pattern of transmission. But it's essential that people follow Covid-appropriate behaviour so that the healthcare system is not stretched," he told the BBC.

Five Indian states are scheduled to hold assembly elections early in 2022 - the Election Commission indicated earlier this week that poll dates may not be postponed even amid the rise in cases.

In India's biggest and politically crucial state of Uttar Pradesh, several politicians including Prime Minister Narendra Modi, have addressed rallies and programmes in which several thousand people - many without masks - participated.

It's a disturbing reminder of the way political parties flouted Covid guidelines in states such as West Bengal - where elections were due - just ahead of the deadly second wave.

Any social gathering, from elections to religious functions, can escalate the transmission of the Omicron variant, warns Dr Fathahudeen.

"We don't need to demonise Omicron, but it's essential that we don't trivialise it either," he says.