New Delhi, Dec. 22: India's health minister has called for a return to Covid-appropriate behaviour, including wearing masks in public, as the country steps up surveillance of cases.

Top health officials have also asked people to get vaccinated and take booster doses.

India relaxed its mask-wearing rules earlier this year after a drop in infection levels.

But a surge in cases in neighbouring China has put the country on alert.

Over the past few months, India reported four Covid-19 cases caused by BF.7, the Omicron subvariant linked to a spike in cases in China.

The cases - three in Gujarat state and one in Odisha - were detected in July, September and November and the patients have recovered, health officials have said.

According to government data, India currently has only around 3,400 active coronavirus cases, but reports of the surge in China have created a sense of fear in the country. Several experts have said that India - which witnessed two deadly waves of Covid in 2020 and 2021 - does not have reason to panic.

On Wednesday, India's health minister Mansukh Mandaviya reviewed the Covid situation in the country and appealed to people to wear masks, maintain social distancing, wash their hands frequently and get vaccinated.

Over 2.2 billion Covid vaccine doses have been administered so far in the country, but only 27% of the population have taken the booster dose - which India calls a "precaution dose" - so far.

On Wednesday, VK Paul, a top government health adviser, appealed to people to use masks and get their booster shots. After more than two years of following strict Covid rules, Indians have mostly stopped wearing masks in crowded places.

The Indian Express newspaper also reported, citing unnamed government officials, that directions had been issued to restart random testing of international passengers at airports.

The country had relaxed air travel guidelines in November, making it optional - "though preferable" - for passengers to wear masks on flights and for international passengers to be fully vaccinated. There has been no official announcement about a change in air travel guidelines yet.

"Covid is not over yet," Mandaviya said in a tweet on Wednesday.

"I have directed all concerned to be alert and strengthen surveillance. We are prepared to manage any situation", he added.

On Tuesday, the federal government also asked states to send Covid samples of all positive patients to labs run by INSACOG, a forum under the health ministry which studies and monitors various strains of Covid in India.-Agencies