JAKARTA (NYTIMES) - Hundreds of children in Indonesia have died from the coronavirus in recent weeks, many of them younger than five, a mortality rate greater than that of any other country and one that challenges the idea that children face minimal risk from Covid-19, doctors say.

The deaths, more than 100 a week this month, have come as Indonesia confronts its biggest surge yet in coronavirus cases overall.

The jump in child deaths coincides with the surge of the Delta variant, which has swept through South-east Asia, where vaccination rates are low, causing record outbreaks not only in Indonesia but also in Thailand, Malaysia, Myanmar and Vietnam.

Indonesia, the world's fourth-most populous nation, this month overtook India and Brazil in the number of daily cases, becoming the new epicentre of the pandemic. The government reported nearly 50,000 new infections and 1,566 deaths among the entire population Friday.

Based on reports from paediatricians, children now make up 12.5 per cent of the country's confirmed cases, an increase over previous months. More than 150 children died from Covid-19 during the week of July 12 alone, with half the recent deaths involving those younger than five.

Overall, Indonesia has reported more than three million cases and 83,000 deaths, but health experts say the actual figures are many times higher because testing has been very limited.

More than 800 children in Indonesia younger than 18 have died from the virus since the pandemic began, but the majority of those deaths have occurred only in the past month.

Health experts said a number of factors contributed to the high number of deaths among children. Some could be vulnerable to the virus because of underlying health conditions such as malnutrition, obesity, diabetes and heart disease.

The country's low vaccination rate is another factor. Only 16 per cent of Indonesians have received one dose, and only 6 per cent have been fully vaccinated. Like other countries, Indonesia does not vaccinate children younger than 12 and only recently began vaccinating those aged 12 to 18.

At the same time, many hospitals have been stretched beyond their limit by the recent surge in cases, with patients waiting in hallways and overflowing tents for a bed in a ward. Few hospitals are set up to care for children with Covid-19.

With hospitals at capacity, about two-thirds of adult patients are in isolation at home, which increases the chances of children being infected.