COLOMBO: Sri Lanka on Saturday extended the nationwide curfew in four high risk districts, including Colombo, till May 4 to stem the spread of the deadly coronavirus in the country, President Gotabaya Rajapaksa 's office announced, a day after the Island nation recorded the highest number of 49 infections in a single day.The four out of the 25 administration districts that come under high risk category are Colombo, Gampaha , Kalutara and Puttalam.For the remaining 21 districts, the curfew will be partially lifted from April 27 till May 1. The partial relaxation for the period will be from 5 am to 8 pm, it said.The government also announced that public and private institutions are allowed to operate from May 4 despite the curfew in the high risk districts.The police had earlier announced that the nationwide curfew imposed to tackle the pandemic will be lifted at 5 am on Monday.Health authorities said that 15 more positive cases were reported on Saturday, taking the country's COVID-19 tally to 435. So far, there have been 7 deaths.The latest extension in the curfew came as the country recorded its highest number of 49 COVID-19 cases for a single day on Friday since its outbreak in March.Sri Lanka has been under a 24-hour curfew since March 20 to combat the deadly viral infection.However, there has been intermittent lifting of the curfew in selected areas which were not seen as dangerous for the spread of the deadly virus.Health officials said that during this week, they have increased the PCR ( Polymerase Chain Reaction ) tests and the aim is to conduct around 100 PCR tests per day.Meanwhile, nearly 4,000 Sri Lankan Navy personnel and their families have been quarantined at a major naval facility after 60 COVID-19 cases were confirmed in the last two days.The COVID-19 has so far infected more than 2.7 million people and killed over 190,000 globally. The US is the worst hit with over 51,000 deaths and more than 905,000 cases, according to Johns Hopkins University