A yellow alert has been sounded in Delhi under the Graded Response Action Plan (GRAP) and restrictions have been imposed accordingly, Chief Minister Arvind Kejriwal said on Monday as Covid cases rise in the city.

The 'yellow' alert restrictions stipulate the closure of schools, colleges, cinemas and gyms with immediate effect.

The Delhi Disaster Management Authority in an order on Tuesday said that shops and establishments of non-essential goods and services and malls will open based on an odd-even formula from 10 AM to 8 PM.

The timing of night curfew imposed from Monday night has also been extended by an hour and it will now begin at 10 pm. The night curfew from 10 pm to 5 am will remain in force till further orders, stated the order issued by the DDMA.

Marriages and funerals will be allowed attendance of 20 persons while all other types of gathering related to social, political, cultural, religious and festival events will be prohibited.

Also, the Delhi Metro will run at 50 per cent of its seating capacity while auto-rickshaws and cabs can ferry up to two passengers. Busses too will ply at 50 per cent of capacity with exempted category passengers, says the GRAP.

The chief minister, after reviewing the Covid situation at a high-level meeting, earlier said virus cases were rising fast in Delhi but there was no need to panic as most people have mild symptoms.

He said although cases were rising in Delhi, there was no increased consumption of medical oxygen or increased demand of beds and ICU facilities which meant most people were getting treated at home.

"We are 10 times more prepared than earlier to deal with the rise in Covid cases," the chief minister said.

"We have stayed above 0.5 per cent positivity rate for more than two days. We are enforcing Level-I (Yellow alert) of the Graded Response Action Plan. A detailed order on restrictions to be implemented will be released soon," he added.

The yellow alert is imposed when the Covid positivity stays above 0.5 percent for two consecutive days. The positivity rate in Delhi has been above 0.5 percent in past two days.

Kejriwal said it was unfortunate that people were visiting markets and malls without masks, and appealed to them to follow Covid appropriate behaviour.

He also urged people of Delhi to follow other Covid rules like masks and social distancing.

The list of restrictions under the yellow alert will be made public later on, he said.

The total number of cases of new Omicron variant of Covid-19 recorded in the national capital has mounted to 165, according to data shared by the Union Health Ministry on Tuesday.

Amid the Omicron scare, Delhi recorded 331 fresh coronavirus cases, the highest single-day rise since June 9 and one death, on Monday, while the positivity rate mounted to 0.68 per cent, according to data shared by the city health department.

India has logged 653 cases of the Omicron variant across 21 states and UTs so far, out of which 186 people have recovered or migrated, showed the Union Health Ministry data updated on Tuesday.

Maharashtra recorded the maximum number of 167 such cases followed by Delhi at 165, Kerala 57, Telangana 55, Gujarat 49 and Rajasthan 46.

Every patient is asymptomatic and all had a travel history. Out of 14 patients the hospital has had, 11 had received three shots of Pfizer Covid vaccine, one person had got Johnson and Johnson vaccine, while one other has been inoculated with Covishield and the other had received Covaxin vaccine, officials said.

Four suspected cases of Omicron are admitted to City Hospital unit of Sir Ganga Ram Hospital, sources said.

All the four people have a travel history and are NRIs, and while two came from France, one each had arrived from the UK and Ghana, they said.

The genome sequencing reports of these patients are still awaited, a source said.

Details from LNJP Hospital are still awaited.

Delhi's first case of the Omicron variant -- a 37-year-old man from Ranchi -- was detected on December 5. He has been discharged.

Amid a jump in Omicron cases reported in Delhi, doctors have warned that people should avoid all kinds of gatherings as this is a highly transmissible variant, and follow Covid-appropriate behaviours, else the situation may worsen.