Authorities in India believe they have reported Asia's first possible death from monkeypox, after a 22-year-old Indian man who had recently returned from United Arab Emirates testing positive died.

Kerala state's health ministry said tests "showed that the man had monkeypox" but it is unclear whether this was the cause of death.

Three monkeypox-related deaths have so far been reported outside Africa in an outbreak that the World Health Organization has declared a global health emergency.

The Indian man died in Kerala on 30 July about a week after returning from the UAE and being taken to hospital in a critical condition, after having a positive test result in Dubai on 19 July.

"The youth had no symptoms of monkeypox. He had been admitted to a hospital with symptoms of encephalitis and fatigue," the Indian Express daily quoted Kerala's health minister Veena George as saying.

Twenty people identified as high risk of infection were being kept under observation, she added, including family members, friends who played football with the man and medical staff.

There were 165 passengers on the same flight from UAE but that "nobody is a close contact", the health ministry said.

Primary tests from the National Institute of Virology in the city of Pune showed that the man had the variant from West Africa, and that more genetic tests would be conducted.

"The disease is nobody's fault. Those who have symptoms should inform the health department so that the spread can be contained," the ministry said, adding that there was "no need to panic".

India has reported at least four cases of the disease, the first on 15 July, in another man who returned to Kerala from the UAE.

Kerala's health ministry said in its statement that a high-level team from the state medical board would investigate the death.

More deaths expected

Spain last week recorded two monkeypox-related deaths and Brazil has reported one.

The WHO's European office said on Saturday that more monkeypox-related deaths can be expected.

"With the continued spread of monkeypox in Europe, we will expect to see more deaths," Catherine Smallwood, Senior Emergency Officer at WHO Europe, said in a statement.

According to the WHO, more than 18,000 monkeypox cases have been detected throughout the world outside Africa since the beginning of May, most of them in Europe.

It is however unclear if monkeypox actually caused the three fatalities, with Spanish authorities as of Sunday still carrying out autopsies and Brazilian authorities saying its deceased patient had other "serious conditions".

The goal needs to be "interrupting transmission quickly in Europe and stopping this outbreak," she said.