Novilia Sjafri Bachtiar reportedly died in a hospital in West Java as Indonesia's data group Lapor COVID-19 informed that at least 31 health workers who died last month had taken the Sinovac vaccine made in China.

Amid a surge in coronavirus cases in Indonesia, reports said the lead scientist behind China's Sinovac vaccine trial Novilia Sjafri Bachtiar died of suspected coronavirus.

China's Sinovac vaccine is being widely used in Indonesia as it grapples with the virus. President Joko Widodo had said on Thursday that "emergency" coronavirus restrictions will be imposed due to the alarming rise of infections in the country.

Local news reports said Bachtiar who was in her early fifties died in a hospital in West Java as she was receiving treatment for the virus. State enterprises minister Erick Thohir confirmed Bachtiar's death declaring it was a "huge loss" at BioFarma which is making the vaccine in Indonesia.

"She was lead scientist and head of dozens of clinical trials done by BioFarma, including COVID-19 vaccine clinical trials in cooperation with Sinovac," Erick Thohir said, adding, "It has been produced and injected into tens of millions of people in Indonesia as part of our effort to be free from this Covid-19 pandemic."

According to the Indonesian Hospitals Association (IHA), 95 per cent of health workers have been vaccinated mostly with China's Sinovac vaccine.

However, according to independent data group Lapor COVID-19, at least 31 health workers who were vaccinated with the Sinovac vaccine died last month, including 50 who have already died this month.

Reports say capital Jakarta including hospitals in West and Central Java have witnessed increased hospitalisations in the past few weeks with the Delta variant being the dominant strain in the country.

Hospitals in the country are reportedly running short of beds with temporary tents being put in many areas to treat coronavirus patients. The virus surge has sparked a huge demand for oxygen with several people reportedly buying it to treat their loved ones at home.

According to the IHA, the demand for hospitalisations has gone up by three to five times with coronavirus cases surging.

On Thursday, Indonesia reported 504 fatalities in the last 24 hours with the number of cases touching almost 25,000 as President Joko Widodo imposed new restrictions which is set to continue until July 20.