- Thiruvananthapuram in India has implemented a "triple lockdown", as the spread of coronavirus intensifies.
- This comes after the area saw an increase in migrants who have tested positive.
- Areas have been sealed off in the Thiruvananthapuram in the new lockdown.
The capital of an Indian state that won praise for its early handling of the coronavirus pandemic has enforced a strict lockdown after a surge in cases, with one minister saying the city was "sitting on an active volcano".
Thiruvananthapuram in the southern state of Kerala implemented what it called a "triple lockdown" this week, as India overtook Russia to record the world's third-highest number of coronavirus infections.
Kerala's strict early measures to curb the coronavirus's spread meant it had just about 100 cases in May, a scenario that propelled its health minister - a retired teacher with a previously low profile - to rockstar status.
But since then nearly half a million people, mostly migrant workers, have arrived back in Kerala from abroad or from other Indian states. On Wednesday, the state recorded the highest single-day spike of 301 infections, taking the total to 6 301.
Kerala's Chief Minister Pinarayi Vijayan, who had voiced concerns about an outbreak if people were not tested before coming back, has attributed the rise in numbers to the returnees, saying they account for more than 80% of coronavirus cases.
"The city seems to be sitting on an active volcano," said Kadakampally Surendran, the state minister in charge of the area, urging people to "strictly follow" the lockdown measures.
Thiruvananthapuram's deputy mayor Rakhi Ravi Kumar said the rise in cases risked becoming unmanageable as people continued to return to the already densely populated city.
Residents are allowed to go out to buy essential items like groceries and medicine only between 19:00 and 11:00 Each neighbourhood can have one shop open.
"People are allowed only to the nearest shop in the area. If they go further, the police will stop and send them back. We are implementing it strictly to prevent the virus from spreading further," she told the Thomson Reuters Foundation.
Neighbourhoods have been sealed with a single entry and exit point under the "triple lockdown", which refers to movement of people and vehicles; households with infected people, and clusters where people who have had contact with infected people live.
People have been advised to stay at home and those who go out must carry signed forms declaring why for police inspection. All offices, businesses and public transport have been shut.
The state has made wearing masks and social distancing mandatory for a year, and banned spitting in public.
Violating these rules can result in a fine of up to 10 000 rupees or two years in prison.
Divya Gopinath, a city deputy commissioner of police, said nearly 220 people were arrested in the first two days of the new lockdown and 208 vehicles seized.
Several states have either already introduced weekend curfews and extended existing lockdowns as the situation worsens.
India has more than 740 000 cases, trailing the United States and Brazil, according to a tally by Johns Hopkins University.