The tally of burials in Jakarta for April is adding to hopes that tough measures to slow the spread of the coronavirus in the Indonesian capital are working, analysts said.

Jakarta laid to rest 4,377 of its deceased last month, not far off March's tally of 4,422 - the highest in at least a decade, said the Parks and City Forests department.

On the one hand, the data paints a grim picture - official tallies may not be keeping up with the surge in Covid-19 deaths as potentially thousands of patients die before test results return from overburdened labs, or never make it to hospital.

The data shows that the death toll over the last two months was more than 2,850 greater than the same period a year earlier. Burials in February were 2,744. Indonesia uncovered its first official coronavirus infection on March 2.

Officially, Covid-19 claimed 371 lives in the city of 10 million last month, out of 792 nationally. The latest figures issued by the government yesterday put the Indonesian death toll in the pandemic at 872.

On the other hand, the data suggests the outbreak is not spiralling out of control as many had feared. A study by the Brookings Institution in February said that even in a mild scenario, the coronavirus outbreak may claim more than 600,000 lives in Jakarta.

"It suggests the true toll is not necessarily trending upward from March," said Mr Kevin O'Rourke, author of the Reformasi Weekly newsletter, referring to the burial data.

To be sure, other factors may be at work. The outset of the epidemic treatment was centred in Jakarta, which in turn put pressure on the capital's cemeteries when patients did not pull through.

And death in Jakarta does not necessarily mean interment in its cemeteries. Wealthier families tend to prefer plots in West Java and Banten, an hour's drive away, potentially keeping a lid on the number of burials the capital saw last month.

Health guidelines require that Covid-19 victims and those suspected of having had it be buried within four hours of death, with the bodies wrapped in plastic to cut the risk of contagion. Nearly 1,600 burials in Jakarta were done this way through April 30. Officials stress that not all the dead had the virus.

Still, April data shows that infection rates and the number of deaths linked to the virus in Jakarta appear to be contracting. Averaging 57 per day during the first seven days of last month, the so-called Covid-19 protocol burials had shrunk to 33 by the final week, according to Jakarta government data.

By the end of April, Jakarta was adding fewer new infections too, averaging 90 in the final week, compared with 105 at the beginning.

Jakarta's non-essential businesses have been closed since mid-March. Most people wear masks and hand sanitisers are available, helping the apparent slowdown in infection, said University of Indonesia epidemiologist Pandu Riono.

But Dr Pandu worries the pandemic may be entering a more challenging phase - spreading out of the big cities and into villages. The government waited until the previous week to seal off the capital, grounding all commercial flights and suspending train services.

Experts worry that the measures came too late. In West Java, Indonesia's most populous province and home to many of Jakarta's migrant labourers, infections doubled in the second half of April to over 1,000.

The country had recorded nearly 10,600 infections as of last Friday - an understatement of the true case load, said Dr Pandu. He said the peak will come in early June. "The infection data we're getting is only the tip of the iceberg," he said.