CHENNAI: It was another heavy day for Tamil Nadu in terms of COVID-19 cases with 98 people, including 91 "same source" contacts, testing positive for the disease, taking the tally rose to 1,173 on Monday as the state government announced extension of the lockdown to check its spread till April 30.

In another related development, wearing of masks was made compulsory with immediate effect from Monday for people in Chennai whenever they step out of their homes, the city civic body said.

Announcing the fresh cases in the state, Health Secretary Beela Rajesh said of the 98 positive cases, as many as 91 of them were 'same source' contacts, an apparent reference to the Tablighi Jamaat congregation in the national capital.

The other seven cases were secondary contacts and included doctors and medical staff, Health Secretary Beela Rajesh said.

The death toll due to COVID-19 in the state remained at 11, she told reporters here.

The number of discharged has increased to 58, she added.

The state had on Sunday registered 106 fresh cases.

Earlier in the day, Chief Minister K Palaniswami announced the extension of the lockdown, valid till Tuesday,saying it was in line with the recommendations of medical and public health experts.

He said the rate of infection in the state has been reined in since the 21-day lockdown was implemented 'vigorously' and it might lead to a spurt in spread of the contagion if the curbs were eased.

In view of the continuation of the lockdown, rice ration card holders will get essential commodities, including rice, toor dhal, sugar and cooking oil free of cost for the month of May too, he said.