Kerala reported the first three COVID-19 cases in India - students returing from China's Wuhan (File)
Parts of Malappuram - a district in north Kerala - have been placed under "triple lockdown" - a containment strategy first implemented in Kerala's Kasaragod district - to prevent further spread of the COVID-19 virus.
The intensive lockdown comes after a spike in fresh coronavirus cases in parts of the district, including those of two doctors, a staff nurse and two paramedical workers in two private hospitals.
They were asymptomatic before being tested as part of the sentinel campaign - the random testing of healthcare officials and workers, as well as others on the frontlines of the battle against the novel coronavirus.
On Saturday Malappuram recorded 47 new cases - 10 from local transmission. Samples of a Tamil Nadu native, who died at the Manjeri Medical College on June 24 also returned positive, Chief Minister Pinarayi Vijayan said Monday.
"Swabs of around 15 children admitted to the hospital where a doctor tested positive are being analysed on priority. We have (also) received a contact list of around 10,000 people and have asked people in those areas, as well as on the list, to maintain a double quarantine period," K Sakeena, the district medical officer, told NDTV.
"The source of infection in many cases is still being traced. The doctors, in particular, are experienced and had lots of patients," the district officer added.
Chief Minister Vijayan said the "triple lockdown" had been implemented in Ponnani taluk of Malappuram from 5 PM Monday to midnight July 6 - a period of seven days.
"The government has decided to conduct extensive tests in Edappal and Ponnani, from where a large number of COVID-19 cases were reported. All those with fever and respiratory problems will be tested. In addition, health workers, hospital staff, bank employees, transport hubs and auto drivers will be tested even if they have no symptoms," the Chief Minister said.
Mr Vijayan also said that medical teams from Kozhikode, Manjeri and Thrissur Medical Colleges will be deployed in these areas.
"They have been instructed to conduct cluster zone tests and house-to-house survey for the next three days. At least 10,000 tests will be conducted in areas where severe infections have been reported," he explained.
Kerala, which reported the first three COVID-19 cases in India, has done well to contain the outbreak so far. There have been only 4,189 confirmed cases with only 22 deaths linked to the virus.
Across India nearly 5.5 lakh cases have been confirmed, with 16,475 of those resulting in deaths.